Resonance Rayleigh Scattering Research Articles

A novel molecularly imprinted nanobifunctional silica probe on the surface of black phosphorus nanosheets for the determination of trace norfloxacin by its catalytic amplification in RRS

A new black phosphorus nanosheets loaded with gold nanoparticles (BPNs-Au) by in-situ reduction procedure were prepared. Using BPNs-Au as the substrate, norfloxacin (NOR) as the template molecule, and 3-aminopropyltriethoxysilane (APTES) as the functional monomer, a surface molecularly imprinted nanosilica probes (BPNs-Au@MIP) with high catalytic properties were rapidly synthesized by the reversed-phase emulsion procedure, and the probes were also characterized in details. It was found that the BPNs-Au@MIP nanoprobe could specifically recognize NOR and had a strong catalytic effect on the nanogold indication reaction of ethanedioic acid-chloroauric acid. The generated AuNPs exhibit strong resonance Rayleigh scattering (RRS) effect and RRS was used as monitoring technique for the nano indicator reaction. After the addition of NOR, the catalytic sites of the nanoprobe were blocked by it, the catalytic activity was reduced, and the RRS signal was linearly weakened. As a result, we constructed a new RRS analysis platform for highly sensitive and selective determination of 0.0625–0.5 nmol/L NOR, with a detection limit of 0.035 nmol/L NOR. The method has been used for the determination of NOR in real samples, and the relative standard deviations (RSDs) were in the range of 3.54–7.43 %, with the recovery of 89.8–109.7 %.

Determination of Aspirin by Resonance Rayleigh Scattering (RRS) Using a Magnetic Molecularly Imprinted Poly(Methacrylic Acid) Probe

Nanosurface-imprinted polymer nanoprobes (Fe3O4@MIP) were prepared by microwave synthesis using Fe3O4 as a nanosubstrate, aspirin as a template, α-methacrylic acid (MAA) as a functional monomer, ethylene glycol dimethacrylate (EGDMA) as a cross-linking agent, and 2,2'-azobisisobutyronitrile (AIBN) as an initiator. Characterization of Fe3O4@MIP revealed that the spectral probe exhibited strong resonance Rayleigh scattering (RRS) for aspirin. With the increase in aspirin concentration, the RRS energy transfer (RRS-ET) was enhanced, and the signal at 370 nm decreased, providing a linear range from 0.25 to 12.5 μmol/L and a detection limit (DL) of 0.08 μmol/L. The developed protocol was used for the determination of aspirin in drugs with recoveries from 93.2 to 102.6.

Mxene Quantum Dot Nanosurface Molecularly Imprinted Polymer Resonance Rayleigh Scattering Probe for Highly Sensitive and Selective Determination of Thiocyanate.

In this article, a nanosurface molecularly imprinted polymer (MQD@MIP) resonance Rayleigh scattering (RRS) spectral probe for SCN- was prepared by sol-gel method, using Mxene quantum dot as a matrix, thiocyanate (SCN-) as a template ion, (3-aminopropyl) triethoxysilane (APTES) as a functional monomer, tetraethoxysilane (TEOS) as the cross-linker, and ammonia as the initiator. The probe produced an RRS peak at 370 nm and exhibits a strong RRS energy transfer (RRS-ET) effect when the MQD@MIP probe identifies SCN-. As the concentration of SCN- increased, the RRS-ET was enhanced, and the signal value of the system decreased linearly at 370 nm, with a determination range of 0.87-5.22 μg/L, and a detection limit of 0.37 μg/L SCN-. This detection method has the characteristics of simplicity, sensitivity, and specific recognition. The RRS method was used to determine SCN- in the sample, with relative standard deviation of 1.95-10.98% and recovery of 89.0-102.8%.

A new SERS quantitative analysis strategy for ultratrace chloramphenicol with Fe3O4@MIP nanocatalytic probe

Three functional magnetic nanocatalytic probe, which integrates recognition, catalytic amplification, and separation enrichment, is a new approach to construct a simple, fast, highly selective, and sensitive analytical method. In this article, a new magnetic nanosurface molecularly imprinted polymer nanoprobe (Fe3O4@MIP) with trifunctionality was rapidly prepared using a microwave-assisted method with magnetic Fe3O4 nanoparticles as a substrate, chloramphenicol (CAP) as a template molecule, and methacrylic acid as a functional monomer. The characterized nanoprobe was found that could specifically recognize CAP, strongly catalyze the new indicator nanoreaction of fructose (DF)-HAuCl4. The gold nanoparticles (AuNPs) exhibit strong resonance Rayleigh scattering (RRS) and surface enhanced Raman scattering (SERS) effects. Upon addition of CAP, the SERS/RRS signals were linearly weakened. Accordingly, a new SERS/RRS analysis platform for highly sensitive and selective determination of CAP was constructed. The SERS linear range was 0.0125–0.1 nmol/L, with detection limit (DL) of 0.004 nmol/L CAP. Furthermore, it could be combined with magnet-enriched separation to further improve the sensitivity, with a DL of 0.04 pmol/L CAP. The SERS method has been used for the determination of CAP in real samples, with relative standard deviations of 2.37–9.89 % and the recovery of 95.24–107.1 %.

A new di-recognition and di-functional nanosurface aptamer molecularly imprinted polymer probe for trace glyphosate with SERS/RRS/Abs trimode technique

A new di-recognition nitrogen-doped carbon dot nanosurface aptamer molecularly imprinted polymer (CDNAg@MIPApt) nanocatalytic di-functional probe was prepared by microwave irradiation. The probe was utilized nitrogen-doped silver carbon dots (CDNAg) as the matrix, glyphosate (Gly) as the template molecule, α-methyl acrylate as the monomer, ethylene glycol dimethacrylate as the cross-linker, and aptamer as the biorecognition element. It could not only recognize Gly but also exhibits catalytic amplification function. It was found that CDNAg@MIPApt catalyzed the redox reaction of polyethylene glycol 400 (PEG400)-AgNO3 to generate silver nanoparticles (AgNPs). The AgNPs indicator component exhibit the effects of surface-enhanced Raman scattering (SERS), resonance Rayleigh scattering (RRS) and surface plasmon resonance absorption (Abs). In the presence of Gly, it binds to the surface imprinted site of CDNAg@MIPApt, to reduce AgNPs generation due to the catalytic activity of CDNAg@MIPApt decreasing. Thus, the SERS/RRS/Abs signal values decreased linearly. The linear ranges of SERS/RRS/Abs assay were 0.1–2.5 nM, 0.25–2.75 nM and 0.5–5 nM respectively. The detection limits were 0.034 nM, 0.071 nM and 0.18 nM Gly.

A new and selective nanogold surface molecularly imprinted methacrylic acid RRS nanoprobe for the determination of trace 4-methylimidazole

A new gold nanosurface molecularly imprinted polymer spectral probe (AuNP-MIP) for the detection of 4-methylimidazole (MI) was synthesized by microwave irradiation, using AuNP as the nanosubstrate, the azo compound (AC) of MI as the template molecule and methacrylic acid (MAA) as the functional monomer. The probe was found to exhibit strong resonance Rayleigh scattering (RRS) effects and to specifically recognize AC. With the increase of MI concentration, the AC increased, the RRS energy transfer (RRS-ET) was enhanced, and the intensity of RRS signal at 370 nm decreased linearly. Accordingly, a new RRS-ET method was developed for the simple, sensitive and selective determination of MI, with the linear range of 0.0375–0.13125 μg/mL, and the detection limit of 0.0022 μg/mL MI. It was applied to analysis of MI in samples, with the recoveries of 91%–100% and relative standard deviations of 1.1%–8.5%.

Carbon quantum dots from hemicucur[6]bit and the application for the detection of Pb2+

A macrocyclic compound, hemicucurbit[6]uril (HemiQ[6]), is employed as the carbon source to produce a novel sort of carbon quantum dots (CQDs) with blue fluorescence in aqueous solution. The CQDs are fully identified by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Nuclear Magnetic Resonance (NMR), zeta potential, ultraviolet/visible (UV–vis) and photoluminescence spectroscopy (PL). The nanomaterial is developed for the analysis of Pb2+ in the light of the Resonance Rayleigh scattering (RRS) changes with the increasing Pb2+ concentration. The proposed probe emerges a high selectivity to Pb2+ and excellent sensitivity in the linear concentration range of 0–6 μM with a detection limit low to 0.42 μM, which is superior to the previous values of Pb2+ sensors, as well as the good anti-interference ability is confirmed by the specifical response to Pb2+ in the presence of other metal cations. Therefore, the proposed analysis of Pb2+ is explored for the application in real samples of tap water and lake water, in satisfied results of acceptable recoveries.

Determination of glycyrrhizic acid as sweeteners by dual-wavelength overlapping resonance Rayleigh scattering

This study used cationic dyes methyl violet (MV) and neutral red (NR) as probes, based on dual-wavelength overlapping resonance Rayleigh scattering (RRS), and designed two highly sensitive methods for the determination of the natural sweetener glycyrrhizic acid (GZA). In the Clark-Lubs buffer solution, when only MV or NR was present in the solution, they formed supramolecular polymers through hydrogen bonding. When adding GZA at different concentrations, the formation of ionic association complexes led to a subsequent decrease in RRS intensity at two wavelengths in the MV − GZA system and NR − GZA system, and the amount of the decline was proportional to the GZA concentration. The linear ranges were determined as 0.1 − 0.6 mg/L and 0.1 − 0.7 mg/L, with correlation coefficients of 0.9972 and 0.9996, and limits of detection were 0.052 mg/L and 0.016 mg/L, respectively. For this study, reaction conditions were optimized, potential interfering substances were investigated, and the mechanisms behind RRS generation and intensity decrease were discussed. The proposed methods were sensitive, fast, time-saving and efficient, and have been successfully applied to licorice and dried ginger decoction analysis, yielding satisfactory results.

Design of resonance Rayleigh scattering and spectrofluorimetric methods for the determination of the antihistaminic drug, hydroxyzine, based on its interaction with 2,4,5,7-tetraiodofluorescein: Evaluation of analytical eco-scale and greenness/whiteness algorithms.

In this work, two validated approaches were used for estimating hydroxyzine HCl for the first time using resonance Rayleigh scattering (RRS) and spectrofluorimetric techniques. The suggested approaches relied on forming an association complex between hydroxyzine HCl and 2,4,5,7-tetraiodofluorescein (erythrosin B) reagent in an acidic media. The quenching in the fluorescence intensity of 2,4,5,7-tetraiodofluorescein by hydroxyzine at 551.5nm (excitation = 527.5nm) was used for determining the studied drug by the spectrofluorimetric technique. The RRS approach is based on amplifying the RRS spectrum at 348 nm upon the interaction of hydroxyzine HCl with 2,4,5,7-tetraiodofluorescein. The spectrofluorimetric methodology and the RRS methodology produced linear results within ranges of 0.15-1.5μg ml-1 and 0.1-1.2μg ml-1, respectively. LOD values for these methods were determined to be 0.047 μg ml-1 and 0.033 μg ml-1, respectively. The content of hydroxyzine HCl in its pharmaceutical tablet was estimated using the developed procedures with acceptable recoveries. Additionally, the application of four greenness and whiteness algorithms shows that they are superior to the previously reported method in terms of sustainability, economics, analytical performance, and practicality.

Development of Eco-Friendly Scattering and Fluorimetric Methods for the Determination of Clemastine Through Its Interaction with Eosin Y: Assessment of Whiteness, Blueness, and Greenness Tools.

For the first time, clemastine was estimated in this work utilizing two validated resonance Rayleigh scattering (RRS) and fluorimetric methods. The methods relied on forming an association complex in an acidic medium between eosin Y reagent and clemastine. In the spectrofluorimetric approach, the investigated drug was quantified by quenching the fluorescence-emission intensity of eosin Y at 543.5nm. The RRS method relied on enhancing the RRS spectrum at 331.8nm, which is produced when eosin Y interacts with clemastine. Suitable conditions were established for the reaction to achieve maximum sensitivity. The linear values obtained from the spectrofluorimetric approach and the RRS method fall into the ranges of 0.2-1.5µg mL- 1 and 0.25-2.0µg mL- 1, respectively. It was established that the detection limits for these methods were 0.045µg mL- 1 and 0.059µg mL- 1, respectively. The developed methodologies yielded acceptable recoveries when used to estimate the quantity of clemastine in its pharmaceutical tablet dosage form. Regarding the use of greener solvents that were chosen, the suggested and reported methods were compared with the help of the Green Solvents Selecting (GSST) tool for assessing hazardous solvents to achieve sustainability. Furthermore, analytical Eco scale and comprehensive assessments of whiteness, blueness, and greenness were carried out utilizing Modified NEMI, ComplexGAPI, and AGREE evaluation tools. Additionally, recently developed tools such as BAGI and RGB 12 were applied to assess the blueness and the whiteness of the suggested methods.

Study on the interaction between erythrosine B and the cardiac drug amiodarone using fluorescence, scattering, and absorbance spectra and their analytical application.

In an acidic buffered solution, erythrosine B can react with amiodarone to form an association complex, which not only generates great enhancement in resonance Rayleigh scattering (RRS) spectrum of erythrosine B at 346.5 nm but also results in quenching of fluorescence spectra of erythrosine B at λemission= 550.4 nm/λexcitation= 528.5nm. In addition, the formed erythrosine B-amiodarone complex produces a new absorbance peak at 555 nm. The spectral characteristics of the RRS, absorbance, and fluorescence spectra, as well as the optimum analytical conditions, were studied and investigated. As a result, new spectroscopic methods were developed to determine amiodarone by utilizing erythrosine B as a probe. Moreover, the ICH guidelines were used to validate the developed RRS, photometric, and fluorimetric methods. The enhancements in the absorbance and the RRS intensity and the decrease in the fluorescence intensity of the used probe were proportional to the concentration of amiodarone in ranges of 2.5-20.0, 0.2-2.5, and 0.25-1.75 μg/mL, respectively. Furthermore, limit of detection values were 0.52 ng/mL for the spectrophotometric method, 0.051 μg/mL for the RRS method, and 0.075 μg/mL for the fluorimetric method. Moreover, with good recoveries, the developed spectroscopic procedures were applied to analyze amiodarone in its commercial tablets.

Dark‐Field Resonance Rayleigh Scattering Biosensor to Monitor Small Molecules and Determine the Secretory Ability of Single Neuron

AbstractAccurate monitoring of small molecules and precise characterization of the secretory ability of neurons are essential for effective diagnosis of neurological diseases. However, existing technologies for monitoring small molecules only provide approximate results. Plasmonic‐based biosensors are a potential solution in this biological application. Nevertheless, optical sensing nanoparticles require precise control of interparticle distance, particle shape and morphology, which can be challenging. This article discovers that the trapping of small molecules to aptamers induces a conformational change that alters the nanostructure of irregularly shaped Au nanoclusters (NCs) and aptamers due to the strong structure‐property relationships of Au NC‐aptamers. This change can be detected via resonance Rayleigh scattering (RRS) intensity in the dark‐field. This new technology overcomes the challenges of precise control of individual nanoparticles and the difficulty of small spectral peak shifts. The Au NC‐aptamers sensing device has a detection limit of 0.112 pm for dopamine, and this work detects 0.226 pm of dopamine surrounding a single epileptic neuron in polarization, which is more than those of healthy neurons. Overall, this easy‐to‐fabricate Au NC‐aptamers‐based technology has a high potential for monitoring small molecules and determining the secretory ability of single neurons, which is not possible using traditional technologies.

A Dimode Scattering Method for Ultratrace Dinitrofuran Detection with Nanopalladium Molecularly Imprinted Polymer Nanocatalytic Probe.

With four nanoparticles as the nanomatrix, dinotefuran (DNF) as the template molecule, N-isopropylacrylamide as the functional monomer, trimethylolpropane and trimethacrylate as the cross-linker, four nanosurface molecularly imprinted polymer (MIP) bifunctional probes were prepared by microwave synthesis. It was found that palladium nanosurface MIP (Pd@MIP) not only recognized DNF but also had the strongest catalytic effect on the new nanogold indicator reaction of acrylic acid-HAuCl4, which was evaluated quickly with the slope procedure developed by us. The generated gold nanoparticles (AuNPs) not only possessed the resonance Rayleigh scattering (RRS) effect but also strong surface-enhanced Raman scattering (SERS) activity. The combination of Pd@MIP with DNF enhanced the catalytic effect by coupling the nanosurface electrons with π-electrons, thus enhancing both scattering signals. A new Pd@MIP nanoprobe catalytic-SERS/RRS dual-mode analytical platform was developed for the specific and sensitive detection of DNF. The linear ranges of the SERS and RRS methods were 0.075-0.75 and 0.1-0.75 nmol/L, and the limits of detection were 0.03 and 0.06 nmol/L, respectively. The standard deviations were 0.54-2.39%, and the recoveries were 93-105%.

Photocleavable DNA Nanotube-Based Dual-Amplified Resonance Rayleigh Scattering System for MicroRNA Detection Incorporating Molecular Computing-Cascaded Keypad Lock Functionality.

Cascade molecular events in complex systems are of vital importance for enhancing molecular diagnosis and information processing. However, the conversion of a cascaded biosensing system into a multilayer encrypted molecular keypad lock remains a significant challenge in the development of molecular logic devices. In this study, we present a photocleavable DNA nanotube-based dual-amplified resonance Rayleigh scattering (RRS) system for detecting microRNA-126 (miR-126). The cascading dual-amplification biosensing system provides a multilayer-encrypted prototype with the functionality of a molecular computing cascade keypad lock. RRS signals were greatly amplified by using photocleavable DNA nanotubes and enzyme-assisted strand displacement amplification (SDA). In the presence of miR-126, enzyme-assisted SDA produced numerous identical nucleotide fragments as the target, which were then specifically attached to magnetic beads through the DNA nanotube by using a Y-shaped DNA scaffold. Upon ultraviolet irradiation, the DNA nanotube was released into the solution, resulting in an increase in the intensity of the RRS signal. This strategy demonstrated a low limit of detection (0.16 fM) and a wide dynamic range (1 fM to 1 nM) for miR-126. Impressively, the enzyme-assisted SDA offers a molecular computing model for generating the target pool, which serves as the input element for unlocking the system. By cascading the molecular computing process, we successfully constructed a molecular keypad lock with a multilevel authentication technique. The proposed system holds great potential for applications in molecular diagnosis and information security, indicating significant value in integrating molecular circuits for intelligent sensing.

Antibody-labeled gold nanoparticle based resonance Rayleigh scattering detection of S100B.

Traumatic brain injury (TBI) is a sudden brain injury due to an external force that causes a large number of deaths and permanent disabilities every year. S100B has been recognized as a potential objective quantitative biomarker for screening the prognosis of TBI and severe head injury. In this article, an anti-S100B monoclonal antibody was immobilized on cysteamine (Cy) functionalized gold nanoparticles (AuNPs) by EDC-NHS chemistry, which enabled S100B resonance Rayleigh scattering (RRS) detection based on antibody-labeled gold nanoparticles. The prepared conjugates were characterized by ultraviolet-visible spectroscopy (UV-vis), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Based on the specific binding of the antibody and antigen, the RRS intensities at 381 nm and 541 nm wavelengths were significantly enhanced, and thus a dual wavelength overlapping resonance Rayleigh scattering (DWO-RRS) method was established. The scattering intensity of the two overlapping peaks was proportional to the concentration of S100B in the range of 0.05-4.5 ng mL-1 with a detection limit of 0.002 ng mL-1. The proposed DWO-RRS method is time-saving, simple, sensitive, and can be used to determine the concentration of S100B in human serum with satisfactory results, which has a promising application in the early diagnosis of TBI.

Rapid and selective RRS determination of ferrocyanide with a nanogold surface molecularly imprinted polymethacrylic acid probe.

In this work, a nanogold surface molecularly imprinted polymer spectral probe (AuNP@MIP) for selectively identifying ferrocyanide was prepared under microwave irradiation using nanogold as the core, ferrocyanide as the template ion, methacrylic acid as the monomer, and ethylene glycol dimethacrylate as the cross-linking agent. AuNP@MIP was found to produce a resonance Rayleigh scattering (RRS) peak at 370 nm. When potassium ferrocyanide (K4Fe(CN)6) was present, a AuNP@MIP-Fe(CN)6 complex was formed, producing RRS-energy transfer (RRS-ET). With an increase in ferrocyanide concentration within a certain range, the RRS intensity at 370 nm decreased linearly, and the detection range was 0.02-0.40 μmol L-1, with a detection limit as low as 0.006 μmol L-1 ferrocyanide. This new method has the advantages of simplicity, rapidity, and selectivity when applied for the determination of K4Fe(CN)6 in table salt.

Integrated resonance Rayleigh scattering approach utilizing Box-Behnken experimental design for the facile quantification of prucalopride in pharmaceutical tablets and human urine with sustainability assessment.

Prucalopride (PCP) is one of the recent drugs used for the regulation of gastrointestinal tract motility and the treatment of constipation. A new, highly sensitive and fast resonance Rayleigh scattering (RRS) approach was suggested for PCP determination. The approach was based on its reaction of PCP with eosin Y in buffered medium (pH 3.5) to form an ion pair association complex which had a significant enhancement in RRS compared to that of eosin Y or PCP alone. The enhancement of RRS intensity had straight correlation to PCP concentration ranging from 150 to 2000 ng mL-1 with 38 ng mL-1 as LOD and 125 ng mL-1 as LOQ. The measurements were done at a wavelength of 365 nm that provided the maximum sensitivity. All the experimental parameters were studied carefully and optimized via Box-Behnken experimental design. The International Council for Harmonization (ICH) guidelines were employed to validate the suggested method and the obtained results proved the appropriate method performance. The method was efficiently utilized to determine PCP in pure form, pharmaceutical tablets and spiked urine samples with no interferences from the surrounding matrices. Furthermore, the greenness of the suggested procedure was confirmed using different green metric approaches.

A new copper nanocluster surface molecular imprinted polymethacrylic acid probe for ultratrace trichlorophenol based on in situ-generated nanogold SPR effects.

A new coinage metal nanocluster surface molecularly imprinted polymethacrylic acid nanoprobe (NC@MIP) for the selective determination of 2,4,6-trichlorophenol (TCP) was prepared via microwave synthesis using 2,4,6-trichlorophenol as a template molecule, copper nanoclusters (CuNC) as a nanosubstrate, and methacrylic acid as a polymer monomer. It was found that the copper nanocluster MIP (CuNC@MIP) shows the strongest catalytic performance for the reduction of HAuCl4 by hydrazine hydrate for the on-site generation of gold nanoparticles (AuNPs) with the surface plasmon resonance (SPR) effects of resonance surface-enhanced Raman scattering (SERS) and resonance Rayleigh scattering (RRS) as well as absorption (Abs). When TCP was added, the CuNC@MIP nanoprobe and TCP-formed CuNC@MIP-TCP nanoenzyme with stronger catalytic activity generated more AuNPs, and the trimodal analytical signal was enhanced linearly. Therefore, a new SERS/RRS/Abs trimodal sensing platform for TCP was constructed, which was simple, rapid, sensitive, and selective. For each mode, the linear ranges were 0.0075-0.075, 0.010-0.10, and 0.010-0.10 nmol L-1, and the detection limits were 0.0010, 0.021, and 0.043 nmol L-1, respectively. The relative deviation of TCP in different water quality was 0.47%-2.5% and the recovery rate was 94.6%-108.6%.

A new and highly efficient CuMOF-based nanoenzyme and its application to the aptamer SERS/FL/RRS/Abs quadruple-mode analysis of ultratrace malachite green.

Malachite green (MG) is highly toxic, persistent, and carcinogenic, and its widespread use is a danger to the ecosystem and a threat to public health and food safety, making it necessary to develop new sensitive multimode molecular spectroscopy methods. In this work, a new copper-based nanomaterial (CuNM) was prepared by a high-temperature roasting using a copper metal-organic framework (CuMOF) as precursor. The as-prepared CuNM was characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy, transmission electron microscopy (TEM), and BET surface area analysis. CuNM was found to catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by H2O2 to produce the oxidation product TMBOX; however, subsequently, the MG aptamer (Apt) could be adsorbed on the CuNM surface by intermolecular interaction, which would inhibit the catalytic performance. After the addition of MG to be tested, the CuNM previously adsorbed by the Apt was transformed into its free state, thus restoring its catalytic activity. This new nanocatalytic indicator reaction could be monitored by surface-enhanced Raman scattering (SERS)/resonance Rayleigh scattering (RRS)/fluorescence (FL)/absorption (Abs) quadruple-mode methods. The SERS determination range was 0.004-0.4 nmol L-1 MG, with a limit of detection of 0.0032 nM. In this way, a rapid, stable, and sensitive method for the determination of MG residues in the environment was established.

Nano-level assay of attention-deficit/hyperactivity disorder medicament, atomoxetine by molecular-size-based resonance rayleigh scattering strategy. Employment in content uniformity, dosage form, and plasma analysis

The psychoanaleptic medication atomoxetine (ATX) is prescribed to cure attention-deficit hyperactivity syndrome. ATX works by selective prevention of norepinephrine reuptake. It acts by raising the brain’s natural level of norepinephrine, which is necessary for behavior regulation. In this study, a sensitive and practical experimental method was employed to analyze the presence of ATX. The approach utilized a green chemistry-compatible technique, known as a one-pot experiment. The main principle behind this method was the use of molecular-size-dependant resonance Rayleigh scattering (RRS) phenomenon, which occurred due to the interaction between the dual complex of Cilefa Pink B and ATX. When ATX medication and Cilefa Pink B were combined in an acidic environment, they formed an association complex, leading to an amplification of the RRS signal. This amplification directly correlated with the concentration of ATX, specifically within the range of 40-1250 ng/mL. The RRS signal was monitored at a wavelength of 352 nm. The sensitivity of the method was demonstrated by the determination of the limit of detection (LOD) at 12.9 ng/mL and the limit of quantitation (LOQ) at 39.2 ng/mL. The variables of the method were thoroughly investigated and optimized. To ensure the reliability of the method, it was validated according to the International Council for Harmonisation (ICH) guidelines. Furthermore, the method was successfully applied to analyze ATX in its prescribed dosage form. The achievement of using the established resonance Rayleigh scattering (RRS) technology to analyze the target drug in plasma and ensure content uniformity was a remarkable feat.