An accurate method was proposed for determining the general stability constants of calcium(II) ions with glycine, L-methionine, and L-tryptophan in an aqueous solution at 298.15 K by recording the spectra of mixtures of calcium(II) and amino acids of various concentrations in the range λ = 190–370 nm with their further processing by multiple linear regression. Differences in the obtained stability constants of complexes of amino acids with calcium(II) were established, and factors influencing their stability were identified. The results expanded the database on the interaction of calcium(II) with amino acids. The obtained results can be used in studies of various processes of biomineral formation in human body, as well as in the development of targeted drugs.

Spontaneous Raman spectroscopy is used to determine rates of an enzymatic reaction. Time dependences of integral Raman intensities in the spectra of reaction mixtures are analyzed. The rates of α-chymotrypsin-catalyzed reaction are determined at different temperatures and pH values.

Coherent anti-Stokes Raman light scattering is investigated in the constant intensity approximation. It is shown that in the nonlinear optical process of scattering the frequency of an intense light wave, it is important to take into account the effects of self-action and cross-interaction, which have a direct effect on the optimal phase relationship between the interacting waves. The spatial behavior of the intensity of the coherent anti-Stokes wave and the phase of both the pump wave and the anti-Stokes component is investigated. As a result of nonlinear interaction of waves, the period of spatial beats changes. The intensity of the antiStokes scattering component is considered as a function of the phase mismatch, the intensities of the pump and the Stokes wave. According to the obtained analytical expressions, the choice of the optimal parameters of the process makes it possible to implement the regime of efficient generation of the anti-Stokes scattering component. The process of generation of the anti-Stokes component of coherent scattering in an optical fiber is compared with the case of generation in a bulk medium. By varying the pump intensity, one can control the intensity of the output coherent radiation of the anti-Stokes component.

The temperature dependence of the electronic absorption and fluorescence spectra of 5,10,15,20-tetrakis-(4-sulfonatophenyl)-porphyrin in weakly acidic aqueous solutions was studied in the temperature range of 288–333 K. It was found that the fraction of molecules in the form of a free base in the ground (S₀) and lower excited singlet (S₁) states increases with the temperature increase, due to a decrease in the fraction of molecules in the doubly protonated form. Deprotonation is caused by a shift in the acid-base equilibrium in the macrocycle core due to a decrease in рK_а(S₀) and рK_а(S₁) with the temperature increase. At solution temperatures >293 K, the difference рK_а(S₁)–рK_а(S₀) < 0, and at Т < 293 K the value рK_а(S₁)–рK_а(S₀) >0. It was found that activation energy of deprotonation in the S₀ and S₁ states is E_a = 5.0 and 3.4 kJ/mol at T > 293 K; it increases to 20.3 and 56.2 kJ/mol at T < 293 K. These differences are explained by different specific solvation of the tetrapyrrole macrocycle in the ground S₀ and lower excited S₁ states due to a change in the proportion of two forms of water. At higher temperatures so-called form A with disordered hydrogen bonding dominates, and when temperature decreases the amounts of the form A and form B, possessing strongly ordered system of hydrogen bonding, are comparable. As a result the porphyrin free base stabilization prevails at high temperatures, whereas the doubly protonated form dominates at lower temperatures.

Phase composition, structural and optical characteristics of thin films of Cu(In_1–xGa_x)(S_уSe_1-y)₂ solid solutions with a chalcopyrite structure were investigated. According to the data of X-ray diffraction analysis the unit cell parameters were a ~ 5.720 Å and c ~ 11.52 Å, and the elemental compositions were x = Ga/(Ga+ In) ~ 0.14 and y = S/(S + Se) ~ 0.11 for Cu(In_1–xGa_x)(S_уSe_1-y)₂ thin films. Optical band gap of Cu(In_1–xGa_x)(S_уSe_1-y)₂ solid solutions was determined from the measurements of photoluminescence spectra and luminescence excitation spectra at a temperature of ~4.2 K and appeared to be equal ~ 1.122 eV. Mechanism of radiative recombination of nonequilibrium charge carriers in thin films of Cu(In_1–xGa_x)(S_уSe_1-y)₂ solid solutions is discussed.

Bifluorophores (5-FAM)₂ and (6-FAM)₂ were synthesized on a 3,5-diaminobenzoic acid framework which allows two fluorophore molecules to be inserted into a single site. Despite the similarity of the structures of the 5- and 6-carboxyfluorescein isomers (5-FАM and 6-FAM), the photo-physical behavior of the corresponding bifluorophores differs. The luminescence quantum yield of (6-FAM)₂ in a buffer solution with pH 8.5 is 2.4 times lower than for (5-FAM)₂. It is shown that structural relaxation of molecules in the excited state slows down as a result of the solution viscosity increasing in the case of using a water-glycerol mixture and the increasing in the microviscosity in the case of micellar solution. This slowing down leads to an increase of the fluorescence intensity, lifetime of excited states and the degree of polarization, i.e. the photophysical properties of the synthesized compounds largely controlled by the viscosity of the medium.

We analytically obtained the frequency dependences of the absorption coefficient profile, taking into account the combined influence of the macroscopic motion of matter, Doppler and Voigt mechanisms of spectral line broadening. The effect of rotation of a spherical plasma on the formation of resonant fluorescence by barium ions upon absorption of laser radiation at a wavelength of 455.4 nm was studied. The deformation of the frequency shape of the laser radiation passing through the plasma and the emission spectrum is due to a shift in the absorption coefficient profile and its broadening caused by the rotational motion of the plasma. An increase in the resonant photons escape from the medium stipulated by the broadening of the emission spectrum of the resonance line is predicted.

We investigated the conditions for forming the single-frequency monopulse operation mode of the transversally diode pumped Yb,Er-phosphate glass laser with a passive Q-switch based on the Co²⁺:MgAl²O⁴ crystal. It was shown experimentally that the spectral selectivity that ensures the stable single-frequency operation for the Yb,Er-laser is achieved in the intracavity Fabry–Perot interferometer in the form of the totally reflecting mirror and nearest end surface of an active element with plane-parallel faces, as well as the polarization interference filter (PIF, Lyot filter). Meanwhile, the PIF created by an active element with thermally induced anisotropy and a polarizer in the form of a passive Q-switch plate, oriented at Brewster’s angle to the resonator axis, acts as a preliminary spectral selector. The maximum energy of the formed output laser pulses was 6 mJ with a duration of 20.2 ns, a repetition rate of 1 Hz, and a singlefrequency lasing spectrum width of 41 MHz.

Methods for detecting Bose-Einstein condensate of light and dark excitons are considered. The features of the result radiation during the decay of condensate excitons are investigated. The recombination of these quasiparticles is studied, taking into account phase synchronism.

Simple, rapid, and sensitive ultraviolet-visible spectroscopy method was used to determine ultra-trace amounts of metformin (MET) in several samples such as drinking water, tablet, serum (blood), and urine without preconcentration step. Gold nanoparticles (AuNPs) were synthesized, and determination of MET was carried out based on the surface plasmon resonance property of AuNPs and the interaction between MET and AuNPs. Transmission electron microscopy (TEM) was utilized to characterize the structure of AuNPs before and after addition MET. Also, dynamic light scattering was used to investigate the size of nanoparticles distribution. The results showed that AuNPs were aggregated in the presence of the MET. Some parameters, including pH, AuNPs concentration, contact time, buffers, and ionic strength, were evaluated to select optimum conditions. Linear range obtained was 15–300 μg/L in the optimum conditions. Also, the correlation coefficient (R²), the limit of detection, and limit of quantification were equal to 0.9918, 0.99, and 1.12 μg/L, respectively. In addition, the effect of interfering species was investigated. Finally, the results of the analysis of different real samples indicated that the proposed method was suitable and accurate for determination of MET.

We investigated the photoconducting and photovoltaic properties of thin film composites based on polyN-epoxypropylcarbazole dopped with molecules of two organic conductors, namely, tetrathiаfulvalene and Ni-dithiolene derivatives. It was established that these composites have hole photoconductivity, and the internal photoeffect is determined by the photogeneration of the charge carriers from the added molecules and the charge transport through the donor fragments of the polymeric matrix.

Using the Raman spectroscopy method we determined the mechanisms of neutrophil activation under the interaction with multi-walled сarbon nanotubes (MWCNTs) functionalized by the COOH groups (MWCNT-COOH) and in complexes with DNA (MWCNT-COOH/DNA). It was revealed that short (100–300 nm) MWCNT-COOH and MWCNT-COOH/DNA, when interacting with neutrophils, cause cytoskeleton reorganization, namely, they activate G-actin polymerization to F-actin in cells. Raman spectroscopy revealed that the investigated CNTs are not phagocytosed by neutrophils. MWCNT-COOH enhance the generation of reactive oxygen and chlorine species by neutrophils, which is confirmed by increasing the NADPH oxidase activity in the cell suspension. The interaction of neutrophils with MWCNT-COOH/DNA leads to the inhibition of the phagocyte oxygen-activating ability and to the formation of neutrophilic extracellular traps with the inclusion of carbon nanostructures. The free radical products generated by neutrophils disrupt the crystal structure of MWCNTs.

We studied the effect of the pulse interval and the number of double laser pulses on the formation of the component and charge composition of laser plasma under the influence of these pulses on the AD1 aluminum alloy target (LSS-1 spectrometer). It is shown that when using the inter-pulse interval in the range 7—16 ms, the concentration of Al ions and their interaction products with oxygen and nitrogen in the air increases by several orders of magnitude compared to the zero interval. The dependence of the process of Al ions formation on the pulse energy is investigated for the case of the 10 ms inter-pulse interval. For the 53 mJ pulse energy, the largest intensity of the Al III ion lines is observed for small (about 15) number of consecutive double pulses in the series. When the number of pulses in the series increases above a certain level (10—20), the intensity of the Al III ion lines decreases by about 5 times, which is due to their active interaction with air molecules and atoms at the exit of the micro-nozzle when the channel shape is changed. The temperature in the plasma region with the maximum Al III content gave values equal to approximately 22000—30000 K. Al nanopowders coated with a layer of aluminum oxide obtained by irradiating an aluminum target with a series of 15 double pulses per point mainly have a size of 50—60 nm.

The active form of iron-containing catalysts – a mixture of iron(II, III) oxides – was studied by Mössbauer spectroscopy in order to identify the mechanism of formation of catalysts used in the upgrading of heavy oil. During the formation process, the iron oxide phase participates in breaking carbon-heteroatom bonds in high-molecular components (resins and asphaltenes) of heavy oil and reduces their molecular mass. Thus, the dispersed iron oxides are enriched with a sulfur-containing phase. Based on the results of mathematical processing of the Мössbauer spectra obtained during the experiment, the quantitative composition of the products of thermocatalytic action at 300°C was studied. Magnetite (Fe₃O₄), greigite (Fe₃S₄), pyrite (FeS₂) and pyrrhotite (Fe_1–xS) were mainly detected in the isolated catalysts. The content of magnetite decreases towards the formation of iron sulfides (pyrite and pyrrhotite). Hydrogen sulfide and hydrocarbons are formed because of cracking, hydrolysis and hydrogenolysis reactions at 300°С.

This study aims to perform a detailed qualitative analysis of astaxanthin isomers. A rapid, open column chromatography method was developed to separate astaxanthin geometrical isomers in gram-scale levels. Chromatographic separation was performed using two silica gel columns with dichloromethane/nhexane/diethyl ether (2:1:1, v/v/v) as elution system. The isolated isomers were identified as all-trans, 9-cis, 13-cis, and 15-cis astaxanthin, according to previously reported C30 high-performance liquid chromatography (HPLC) analysis data. Further, the fine structure of the single 9-cis astaxanthin isomer, as well as all-trans astaxanthin, was determined successfully for the first time by Fourier-transform infrared spectroscopy (FT-IR), one-dimensional ¹H and ¹³C nuclear magnetic resonance (NMR) spectroscopy, and twodimensional homonuclear correlation and heteronuclear correlation NMR spectroscopy.

A universal method for the quantitative determination of oxytetracycline in three water-based medicinal drugs using Raman spectroscopy has been developed. A comparison is made of five calibration models based on different mathematical data processing: one-dimensional calibration (Beer-Lambert Law, classical least squares, stepwise multiple linear regression) and multi-dimensional calibration (partial least squares and principal component regression). It is found that the most accurate quantitative determination results are achieved when using a calibration model based on partial least squares using two principal components.

Erbium-doped fiber amplifiers are used for amplifying optical signals. In this type of optical amplifier, the core of a silica fiber is doped with Er³⁺ ions. Here, the effects of temperature on the gain parameters for short-length erbium-doped fiber amplifiers are simulated. Temperatures were selected over a wide range (-200 to +80°C) for different ion densities to simulate extreme conditions, such as the presence of liquid nitrogen. The maximum gain occurs at temperatures close to 0°C, and the Er³⁺ concentration also plays an important role.

We aim to show the effectiveness of the double density dual-tree complex wavelet transform to denoise the Raman signal. A comparative study is carried out of the double density dual-tree complex wavelet transform with the discrete wavelet transform, dual tree complex wavelet transforms, and Savitzky–Golay smoothing method to show its capability and effectiveness. Results show that denoising based on the double density dual-tree complex wavelet transform can improve the quantitative and qualitative analysis of the Raman signal.

The spatial-energy profiles of the recorded energy of reflected rectangular and real-form pulses are studied. The values of the maximum signal, the position of the maximum and the size of the best visibility area were studied as a function of the delay distance at different ratios between the pulse durations and the signal registration times.

Multivariate methods were applied to the transmission spectra of pharmaceutical products obtained using the fast Fourier transform of the temporal forms of the terahertz electromagnetic field. Successive use of the principal component analysis and linear discriminant analysis allowed us to classify two drugs, and by the independent component analysis to recover the spectrum of the first component in a mixture of three drugs and identify the characteristic feature of the second.

The spectra of sixteen optical functions of the group of compounds Mg₂X (X – Si, Ge, Sn) in the range of 1—11 eV at 77 K have been determined and compared. Their main features and general regularities have been established and compared. The calculations are performed on the basis of the experimental reflection spectra R(E) using the Kramers–Kronig relations and analytical formulas connecting optical functions. The integral spectra of the imaginary part of the dielectric function e2(E) are decomposed into elementary transition bands in the 1.5–6.0 eV region using an improved nonparametric method of combined Argand diagrams, taking into account the effective number of valence electrons forming individual elementary bands. For Mg₂X compounds (X – Si, Ge, Sn), instead of five to six maxima and shoulders in the integral spectra, an average of six times more elementary components of transitions caused by excitonic and interband transitions were revealed. The energies of the maxima and areas of the selected elementary components of the transition bands of three compounds are determined and compared. On the basis of the known theoretical calculations, the supposed nature and localization for the revealed elementary components of the transitions are proposed. A diagram is proposed for the dependence of the energies of the maxima of the selected transition bands on the lattice parameter of the three compounds.

The possibility of volumetric phase recording based on photooxidation of side anthracene groups of a new polymer with a glass transition temperature of about 338 K by oxygen entering the layer through the boundary with the air medium has been experimentally established. Volumetric holographic gratings with a maximum diffraction efficiency of 2.5–9.5% are recorded by radiation from a He-Ne laser (l = 633 nm) in layers 5–20 µm thick. It is shown that in the layers thicker than 10 µm the diffraction efficiency is limited by the saturation of the growth of the modulation depth of the optical path difference. The phenomenon is associated with an increase in the radius of the photorefraction sphere around the photosensitizer molecule with a deepening of the photoconversion of anthracene groups, which reduces the resolution of the holographic grating and its effective thickness.

The rapid development of nanoparticles (NPs) and their broad applications in medicine caused concerns about biological effects and biosafety. Here, the interaction of silver NPs (AgNPs) and trypsin is studied with ultraviolet-visible spectra, circular dichroism, and fluorescence spectra. Trypsin is exposed to various sizes and concentrations of AgNPs. The intensities of the trypsin ultraviolet-visible absorption peaks are proportional to the AgNP concentration and size. In the circular dichroism spectra, there was evidence that AgNPs affected the secondary structure of trypsin. Fluorescence spectra show that the formation of the protein-nanoparticle complexes alters the protein chromophore chemical environment or structure and quenches its fluorescence. Hence, the extent of AgNP binding of trypsin depends on both NP concentration and size, and changes the AgNPs physicochemical properties as well as the trypsin secondary structure. With regard to nanomaterial safety, the interaction of NPs with proteins must be explored further for establishing NP toxicity and design guidance.

The objective of this work was to evaluate the ability of the functionally enhanced derivative spectroscopy (FEDS) algorithm to characterize the surface of microorganisms, namely, Candida albicans, by mid-IR spectroscopy and with the cellulose sensing surface technique. This work is a key stage in the study of cellcell and cell-surface interactions between microorganisms, including the study of polymicrobial biofilms. Accordingly, C. albicans was selected as a microorganism model due to its importance in medical science and human health. Spectra were recorded in triplicate from 4000 to 500 cm^–1 by the ATR technique. It was concluded that the FEDS transform of the mid-IR spectrum is a powerful analytical tool to improve spectral analysis by IR spectroscopy. In the particular case of C. albicans biofilms, it was observed that by FEDS, it is possible to deconvolute signals and achieve improved signal differentiation. For interpretation, serine, threonine, glycine, alanine, glutamic acid, proline, and N-acetyl-D-glucosamine units were taken as molecular models since these molecules have been described as the main components in the cell wall of C. albicans. In this way, it was found that the vibrational spectrum of C. albicans biofilms can be understood considering only the main components of the cell wall.

Synergetic chemical interaction of various phytochemicals in Amruthotharam kashayam, a Polyherbal formulation, has been evaluated by different spectroscopic techniques. Comparative chemical profiling was done along with its ingredient plants by HPTLC analysis. Characterization of major chemical constituents was carried out by Fourier transform infra-red spectroscopy (FTIR) and tandem mass spectroscopic analyses (LC/MS-MS). The chromatographic profiling and spectrophotometric studies revealed that the chemistry of the finished formulation is different from that of individual plant extracts. FTIR analysis showed the spectral shift in the formulation when compared with corresponding transmittance in the ingredient plants. The synergetic chemical reaction during the process is evidenced by such specific spectral shift. The tandem mass spectroscopic studies also confirmed the chemical transformations happening during the preparation of Amruthotharam kashayam.

The objective of this study was to confirm whether near infrared spectroscopy could be used to discriminate the infected silkworm chrysalises. A total of 105 silkworm chrysalises – 65 infected and 40 uninfected – were collected at Beijing Shoucheng Agricultural Development Co., Ltd. Near infrared spectra were acquired at the head, chest, abdomen, and posterior belly of each silkworm chrysalis (both uninfected and infected). Three spectral pre-processing methods and four discrimination models were used to identify the uninfected and infected silkworm chrysalises. Results indicated that the PLS-DA model based on the spectra processed by multiplicative scatter correction (MSC) had the best discrimination performance (the prediction accuracy of calibration set and prediction set were 100 and 97.5%, respectively), and the head portion was the best position for the discrimination of uninfected and infected silkworm chrysalises. The overall conclusion was that the uninfected and infected silkworm chrysalises could be successfully identified by using near infrared spectroscopy technology in the cultivation of Cordyceps militaris.

Experiments were conducted to develop and assess a method by which the water content of a lettuce canopy can be nondestructively detected and estimated using a combination of spectra, RGB images, and canopy temperature. To this end, 130 lettuce samples grown in four different substrate water content levels were collected for data acquisition. In the spectroscopy procedure, five spectral intervals (380 variables) were selected by backward interval partial least squares and were further reduced to 48 wavelength variables, chosen using a genetic algorithm based on Savitzky–Golay smoothing and log (1/R) transformation. Then, 967, 1170, 1221, 1406, 1484, 1942, and 1985 nm optimum spectral variables were selected by the successive projection algorithm. Thirteen plant features were extracted from top- and front-view RGB images. These features comprised morphological, color, and textural features. An empirical crop water stress index was established based on dry and wet reference surfaces via thermal imagery. Subsequently, a principal component analysis was applied to the spectral variables and the image features, and an extreme learning machine was used to construct the multisensor and single-sensor models. The results show that the multisensor model had a correlation coefficient of prediction of 0.9018, which was found to be approximately 9.4 and 15.7% better than that of the spectral and image models. This work demonstrates that integrating spectra, RGB images, and canopy temperature with suitable algorithms offers a high potential for use in the nondestructive measurement of water content in lettuce, considerably improving accuracy over that using a single-sensor modality.

We have experimentally realized a morphology-directed nanoscale energy transfer between an emitter, Eosin yellow dye, and three distinct gold nanoshapes, namely, nanospheres, nanopebbles, and nanoflowers. Raman spectroscopy is employed to ensure mutual interaction among the couple hybrids. The results explicitly show that plasmonic structures with sharp edges produce a strong localized electromagnetic field, which substantially suppresses the background fluorescence signals of the analyte. Further, the relationship between the observed quenching of the dye fluorescence and the geometrical factors of the gold nanoshapes is used to comprehend the influence of energy transfers on their enhanced third-order nonlinearity. The experimental findings reveal a relationship between the efficiency of energy transfers and the enhancement of the observed nonlinear optical coefficients. This study may act as the basis for designing active photonic nanocomposites based on their efficient energy transfer interactions.

The aim of this study was to analyze the composition of urinary stones and gallstones and assess their prevalence as a function of age and sex. A total of 425 urinary stones and 108 gallstones was analyzed for composition using FTIR-ATR spectroscopy. According to the absorption band spectra obtained using FTIR-ATR, urinary stones were classified into the following groups: calcium oxalate (55.6%), uric acid (24.1%), hydroxyapatite (7.3%), struvite (9.0%), brucite (2.1%), cystine (1.0%) and ammonium urate (0.2%). Gallstones were classified into cholesterol (66.7%) and pigment stones (33.3%). As to urinary stones, they are more common in males (62.0%) than in females (38.0%) (ratio ♂/♀: 1.7), calcium oxalate stones being the most common ones in both sexes. Women have a higher frequency of hydroxyapatite and struvite than men (p<0.05) whereas males have a higher frequency of calcium oxalate and uric acid than women (p<0.05). Calcium oxalate stones are more common in the 30–69 years age group (p<0.05), while uric acid stones are more common in ages >50 years (p<0.05). As to gallstones, they are more common in women (59.3%) than in men (40.7%) (ratio ♀/♂: 1.4), cholesterol stones being the most prevalent in both sexes. Women have greater frequency of cholesterol stones than men (p<0.05) and men have higher frequency of pigment stones than women (p<0.05). Cholesterol stones were more common in ages <60 year (p<0.05), whereas pigment stones were more common in ages ³60 years (p<0.05). The results of this study show that the physical analysis of stones using FTIR-ATR spectroscopy provides fairly accurate information on its composition, and sex and age have been seen to have an influence on the type of stone formed.

Determining the concentration of polycyclic aromatic hydrocarbons (PAHs) in water is vital for reducing negative effects on human health, such as cancer and malformation. This study proposed an alternative analytical method based on surface enhanced Raman spectroscopy and kernel principal components analysis combined with support vector regression (SVR) for the determination of PAH concentration in water. For this, a dataset containing 300 Raman spectra of polycyclic aromatic hydrocarbon mixtures was made using naphthalene (NAP), pyrene (PYR), and phenanthrene (PHE) with concentrations ranging from 0 to 1000 ppb. In order to improve the effect of the model detection, different pre-processed methods were applied: normalization, multiplicative scatter correction, detrending, standart normal variate transformation, and Savitzky–Golay smoothing. For comparison, partial least squares (PLS) and SVR with the polynomialkernel were also used. The pre-processing method with the best prediction effect was SNV for all the three substances. For NAP, the optimal correlation coefficient of cross-validation (R_cv), correlation coefficient of prediction (R_pred), RMSECV, RMSEP, and RPD are 0.90, 0.937, 138.9, 117.4, and 2.9 ppb, respectively, while for PYR the optimal R_cv, R_pred, RMSECV, RMSEP, and RPD are respectively 0.881, 0.897, 152.3, 142.8, and 2.3 ppb. For PHE, the optimal R_cv, R_pred, RMSECV, RMSEP, and RPD are 0.980, 0.982, 64.5, 62.9, and 5.3 ppb, respectively. This study provides a new method with a better prediction effect for quantitative analysis of low concentrations of polycyclic aromatic hydrocarbons in water by using surface enhanced Raman spectroscopy.

This study aims to detect β-lactam antibiotics using a conjugated antibody with gold nanoparticles (GNPs). For this purpose, the gold nanoparticles synthesized from Chinese lettuce leaf extract (as reductant) were used for the colorimetric detection of β-lactam antibiotics (such as ampicillin, amoxicillin, penicillin G, oxacillin, and carbenicillin). XRD, FTIR spectroscopy, TEM, and dynamic light scattering were utilized to detect the crystallinity, to identify functional groups involved in the synthesis of GNPs, and to measure the size of the GNPs; pH 8 and a concentration of 8.4 μg of antibody at 1 mL GNPs solution were selected as the best pH and concentration of antibody for the conjugation of antibody with GNPs. The maximum wavelengths of the colloidal GNPs, conjugation of antibody with GNPs, and detection of antibiotics (from 1 nM to 1 mM) with GNPs-PAb were recorded using a micro-volume spectrophotometer system. The results indicated that the localized surface plasmon resonance spectrometer absorption wavelength of GNPs red-shifted with increasing concentration of β-lactam antibiotics. With increasing concentration of ampicillin, penicillin G, and carbenicillin, the wavelength of maximum changed, and after saturation of antibiotics concentration, the curve reaches a plateau. This indicated that the antibody showed similar behavior in the detection of these antibiotics. But regarding amoxicillin, the saturation concentration is much higher, indicating that the antibody was more specific for its detection. In contrast, for oxacillin, saturation occurred very soon, which demonstrated that the antibody had an extremely low detection capability for this antibiotic. Finally, the results showed that the antibody was sensitive to 1 nM of the five β-lactam antibiotics studied.