Functionalized Silver Nanoparticles Research Articles

Radiolabeling and cytotoxicity of monoclonal antibody Isatuximab functionalized silver nanoparticles on the growth of multiple myeloma

The goal of this article was to develop a new therapeutic strategy based on nanotechnology for multiple myeloma (MM) treatment which shows a synergism of different mechanisms. In this concern, 12.9 nm-sized silver nanoparticles (AgNPs) were prepared and functionalized with Isatuximab, anti-MM monoclonal antibody (mAb). Furthermore, the synthesized nanocomposite was radiolabelled with iodine-131 radionuclide and yielded 95.5 ± 1.5%. Then, the synergistic MM-proliferation inhibition efficacy of the radionanocomposite (131I-Isatuximab/AgNPs) was explored in-vitro in comparison to each single agent. The MTT investigation showed that the antiproliferation effect of 131I-Isatuximab/AgNPs increased by more than 1.5 fold if compared with Isatuximab, AgNPs, Isatuximab/AgNPs or 131I-Isatuximab. Additionally, 131I-Isatuximab/AgNPs exhibited an apoptotic effect on MM cells which was more than that of Isatuximab, AgNPs, Isatuximab/AgNPs or 131I-Isatuximab by 2, 1.8, 1.7 and 1.5 folds, respectively. In conclusion, the results expressed 131I-Isatuximab/AgNPs as a potential new anti-MM agent.

Organic Waste as Reducing and Capping Agents for Synthesis of Silver Nanoparticles with Various Applications

AbstractCurrently, the large amount of organic waste produced represents one of the leading environmental problems. According to United Nations, every year a third of all food produced ends up rotting and, therefore, becoming waste. Its use and revalorization represent an attractive alternative in the search for solutions to this situation. In this context, these residues can be used to obtain extracts beneficial for nanotechnology, acting as a reducing and stabilizing agent to produce metal nanomaterials such as silver nanoparticles by green synthesis, an ecofriendly and nontoxic method. Silver nanoparticles have been applied in applications as antibacterial, antifungal, and catalytic agents, as well as antioxidants, biosensors, and treatment of various diseases. Thus, this review contributes to fostering and promoting a sustainable environmental awareness through the reuse and revalorization of organic waste, which allows the sustainable biosynthesis of functional silver nanoparticles to be widely applied successfully in various fields of application.

A surface-enhanced Raman scattering aptasensor for Escherichia coli detection based on high-performance 3D substrate and hot spot effect

A surface-enhanced Raman scattering (SERS) aptasensor was established for highly sensitive and selective detection of Escherichia coli (E. coli). Chitosan hydrogel modified with E. coli aptamer (Apt) functionalized silver nanoparticles was constructed as a SERS 3D substrate for specific bacteria enrichment, while the Raman signaling molecule 4-mercaptobenzoic acid and E. coli Apt modified gold nanostars were prepared for the sensitive quantification of E. coli. The aptasensor exhibits intense electromagnetic field enhancement in multiple hot spot regions, including the spikes and the gap between adjacent nanostars and that between gold nanostars and silver nanoparticles. Due to the hot spot effect coupled with the selective recognition ability, a detection limit of 3.46 CFU/mL with a wide dynamic linearized range from 3.2 × 101 to 3.2 × 107 CFU/mL could be achieved without other non-target bacteria interference. Moreover, this SERS aptasensor was applied to detect E. coli in actual samples with a good recovery rate (>90%). Therefore, the developed SERS aptasensor paves a new avenue for the detection in the field of food safety and environmental pollution by replacing the corresponding aptamers.

Size and Zeta Potential Clicked Germination Attenuation and Anti-Sporangiospores Activity of PEI-Functionalized Silver Nanoparticles against COVID-19 Associated Mucorales (Rhizopus arrhizus).

The SARS-CoV-2 infections in Indian people have been associated with a mucormycotic fungal infection caused by the filamentous fungi Rhizopus arrhizus. The sporangiospores of R. arrhizus are omnipresent in the environment and cause infection through inhalation or ingestion of contaminated air and foods. Therefore, the anti-sporangiospore activity of polyethyleneimine functionalized silver nanoparticles (PEI-f-Ag-NPs) with variable size and surface charge as a function of the molecular weight of PEI was explored. The results showed that both PEI-f-AgNP-1 and PEI-f-AgNP-2, potentially, attenuated the germination and reduced the viability of sporangiospores. Furthermore, the results showed that the minimum inhibitory concentration (MIC) values of both PEI-f-AgNP-1 and PEI-f-AgNP-2 (1.65 and 6.50 μg/mL, respectively) were dependent on the nanoparticle size and surface ζ potentials. Similarly, the sporangiospore germination inhibition at MIC values was recorded, showing 97.33% and 94% germination inhibition, respectively, by PEI-f-AgNP-1 and 2 within 24 h, respectively. The confocal laser scanning microscopy, SEM-EDS, and confocal Raman spectroscopy investigation of PEI-f-Ag-NPs treated sporangiospores confirmed size and surface charge-dependent killing dynamics in sporangiospores. To the best of our knowledge, this is the first investigation of the polyethyleneimine functionalized silver nanoparticle-mediated size and surface charge-dependent anti-sporangiospore activity against R. arrhizus, along with a possible antifungal mechanism.

Synthesis of phenylbenzotriazole derivative stabilized silver nanoparticles for chromium (III) detection in tap water

A selective and sensitive colorimetric method was developed for the detection of chromium (III) in tap water using phenylbenzotriazole (PBT) derivative functionalized silver nanoparticles (PBT-AgNPs). The PBT functionalized nanoparticles were synthesized at room temperature by reducing with sodium borohydride (NaBH4). The nanoparticles were characterized by UV–Vis spectroscopy, Zetasizer, Fourier Transformer InfraRed (FTIR), Scanning Electron Microscope (SEM) and Atomic Force Microscopy (AFM). The elevated temperature, pH and higher ionic strength of electrolyte had insignificant effect on stability of the nanoparticles. The PBT-AgNPs were then tested as a probe and were found highly sensitive to the presence of Cr (III) and showed excellent selectivity in the presence of other interfering metals ions. The Jobs plot confirmed the binding ratio between the nanoparticles and Cr (III) to be 1:2. The Surface Plasmonic Resonance (SPR) band quenching as function of concentration showed good linear response (R2 = 0.9992) with limit of detection of 0.2 µM. The PBT-AgNPs were also applied as sensing probe for determination of Cr (III) in tap water samples. These experimental finding showed the supramolecular stabilized silver nanoparticles as a simple, selective, and easy alternative for detection of Cr (III).

SPR-based assay kit for rapid determination of Pb2+

A recyclable optical nanosensor was developed by immobilizing l-tyrosine functionalized silver nanoparticles (AgNPs) on the polyethylene terephthalate (PET) substrate for rapid determination of Pb2+ ions. At first, the l-tyrosine functionalized AgNPs were assessed in the solution phase; the response time was lower than 15 s, and a limit of detection lower than 9 nM was obtained in the dynamic range of 1–1000 nM. For fabrication of the optical assay kit, the design of experiment (DOE) was used to optimize the immobilization efficiency of the nanoparticles on PET films by studying AgNO3 concentration and pH as two crucial parameters. The assay kit in optimal conditions showed a sharp localized surface plasmon resonance band suitable for sensitive determination of Pb2+. The fabricated sensor showed promising results for rapid determination of lead ions with the limit of detection value as low as 1 nM (S/N = 3). The sensor reproduced the obtained results even after three consecutive runs, which proved the recyclability of the optical assay kit. The recoveries of the spiked concentration in real samples were in the range of 95%–103%, which confirmed the applicability of the sensor in practical applications.

Plasmonic Nano Silver: An Efficient Colorimetric Sensor for the Selective Detection of Hg2+ Ions in Real Samples

Environmental pollution caused by heavy metal ions has become a major health problem across the world. In this study, a selective colorimetric sensor based on starch functionalized silver nanoparticles (St-Ag NPs) for rapid detection of Hg2+ in real samples was developed. The environmentally friendly green approach was utilized to synthesize starch functionalized silver nanoparticles (St-AgNPs). A multi-technique approach involving UV-Vis absorption spectroscopy, Fourier transform infrared (FT-IR), X-ray diffraction (XRD), and scanning electron microscope (SEM) was used for the characterization of St-Ag NPs. These starch functionalized AgNPs were tested for the detection of heavy metals at 25 °C. The screening process revealed clear changes in the AgNPs color and absorption intensity only in the presence of Hg2+ due to the redox reaction between Ag0 and Hg2+. The color and absorption intensity of nanoparticles remain unchanged in the presence of all the other tested metals ion. The proposed method has strong selectivity and sensitivity to Hg2+ ions, with a detection limit of 1 ppm revealed by UV-visible spectrophotometry. The proposed procedure was found to be successful for the detection of Hg2+ in real samples of tap water.

Plasma-assisted in-situ preparation of L-cystine functionalized silver nanoparticle: An intelligent multicolor nano-sensing of cadmium and paracetamol from environmental sample

L-cystine (L-cys) functionalized plasmonic silver nanomaterial (Ag NPs) was fabricated toward the selective and sensitive detection of paracetamol and cadmium. The prepared L-cys-Ag nanoparticles (NPs) were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD) and fourier transform infrared spectroscopy (FTIR) analyses. SEM imaging show that Ag NPs was decorated on the surface of L-cysteine 3D cubic nanosheet. L-cys-Ag NPs showed selective and sensitive detection towards paracetamol and cadmium. The interference study confirms that the presence of other metal ions didn’t inhibit the detection of cadmium by L-cys-Ag NPs. The limit of detection of paracetamol and cadmium by L-cys-Ag NPs was calculated to be 1.2 and 2.82 nM respectively. In addition, the real sample detection of paracetamol on blood serum and urine, and cadmium on STP were performed and the recovery percentage was above 97%. Further, the real sample analysis was performed in tap and drinking water and the recovery percentage was more than 98%. The analytic logic gate on the multicolour detection of cadmium and paracetamol was performed for the semi-quantitative monitoring of paracetamol and cadmium by L-cys-Ag NPs. The developed L-cys-Ag NPs were found to be an effective tool for the monitoring of cadmium in environmental water bodies and paracetamol in blood and urine.

Sensitive determination of Norfloxacin in milk based on β-cyclodextrin functionalized silver nanoparticles SERS substrate

The norfloxacin (NFX) residue in milk will increase human resistance to drugs and pose a threat to public health. In this work, a highly sensitive method for detection of NFX was developed based on surface enhanced Raman spectroscopy (SERS) using β-cyclodextrin functionalized silver nanoparticles (β-CD-AgNPs) as substrate. The unique spatial size and hydrophilicity of β-CD on the surface of AgNPs could selectively capture the target molecule (NFX) through some weak interactions, including hydrogen-bond interaction, electrostatic interaction, etc. The interactions were characterized by the UV–Vis absorption spectroscopy, fluorescence spectroscopy, Zeta potential and DLS. The Raman signal of NFX is largely enhanced when anchored by β-CD on the surface of AgNPs due to SERS effect. Through a series of experiments and analysis, the limit of detection (LOD) in standard solution and spiked milk were calculated to be 3.214 pmol/L and 5.327 nmol/L. The correlation coefficients (R2) were 0.986 and 0.984, respectively. For milk sample determination of NFX, the recovery was 101.29% to 104.00% with the relative standard deviation (RSD) from 2.986% to 9.136%. To sum up, this developed SERS strategy is sensitive and specific to detect NFX in milk, it has practical application value and prospects.

Biogenic Synthesis of Antibacterial, Hemocompatible, and Antiplatelets Lysozyme Functionalized Silver Nanoparticles through the One-Step Process for Therapeutic Applications

To evaluate silver nanoparticles’ (AgNPs) therapeutic and clinical potentials, antibacterial action, blood compatibility, and antiplatelet activities are the main concerns for toxicity profiling. Heat-denatured lysozyme-mediated formulation stabilized the AgNPs, thereby providing more bactericidal activity and blood compatibility. The study of the synthesis of AgNPs suggests the rapid and cost-effective formulation of AgNPs by one-step reaction using a 10:1 ratio of silver nitrate and lysozyme by incubating at 60 °C for two hours. Characterization of AgNPs was analyzed by UV–Visible spectroscopy, DLS, TEM, EDX, XRD, AFM, and FTIR, followed by antibacterial, hemocompatibility, and platelet aggregation testing. The average size of synthesized AgNPs was found to be 94.10 nm with 0.45 mV zeta potential and 0.293 polydispersity index by DLS. The TEM and EXD results indicated homogeneously 28.08 nm spherical-shaped pure formations of AgNPs. The XRD peaks showed the synthesis of small AgNPs with a crystallite size of 22.88 nm, while the AFM confirmed the homogeneity and smoothness of the monodispersed AgNPs. The FTIR spectra specified the coating of the lysozyme-derived amide group on the AgNPs surface, which provides stability and functionality of nanoparticles. The antibacterial activity of AgNPs was remarkable against six pathogenic bacteria and three multidrug resistance (MDR) strains (i.e., Escherichia coli, Klebsiella aerogenes, and Pseudomonas aeruginosa), which exhibited inhibition zones with diameters ranging between 13.5 ± 0.2 mm to 19.0 ± 0.3 mm. The non-hemolytic nature of the AgNPs was calculated by percentage hemolysis with four concentrations. The negative result of platelet aggregation using platelet-rich plasma suggests the antiplatelet effect of AgNPs. Only minor hemolysis of 6.17% in human erythrocytes and mild platelet aggregation of 1.98% were induced, respectively, by the use of 1000 µL of 1 mM AgNPs, which contains approximately 107.8 μg silver. The results indicated that the antiplatelet potency and non-hemolytic nature with the antibacterial action of the lysozyme functionalized AgNPs have a good chance to be used to solve in-stent restenosis and thrombosis issues of the coronary stent and may also have a possibility to use in vaccination to resolve the blood clotting problem. So, the optimized biogenic formulation of AgNPs offers promising opportunities to be used as a therapeutic agent.

Functionalized Silver Nanoparticles as Selective Colorimetric Sensors for Fe3+

Functionalized Silver Nanoparticles as Selective Colorimetric Sensors for Fe3+

Accumulation, Chronicity, and Induction of Oxidative Stress Regulating Genes Through Allium cepa L. Functionalized Silver Nanoparticles in Freshwater Common Carp (Cyprinus carpio).

Green evolutionary products such as biologically fabricated nanoparticles (NPs) pose a hazard to aquatic creatures. Herein, biogenic silver nanoparticles (AgNPs) were synthesized by the reaction between ionic silver (AgNO3) and aqueous onion peel extract (Allium cepa L). The synthesized biogenic AgNPs were characterized with UV-Visible spectrophotometer, XRD, FT-IR, and TEM with EDS analysis; then, their toxicity was assessed on common carp fish (Cyprinus carpio) using biomarkers of haematological alterations, oxidative stress, histological changes, differential gene expression patterns, and bioaccumulation. The 96h lethal toxicity was analysed with various concentrations (2, 4, 6, 8, and 10mg/l) of biogenic AgNPs. Based on 96h LC50, sublethal concentrations (1/15th, 1/10th, and 1/5th) were given to C. carpio for 28days. At the end of experiment, the bioaccumulations of Ag content were accumulated mainly in the gills, followed by the liver and muscle. At an interval of 7days, the haematological alterations showed significance (p < 0.05) and elevation of antioxidant defence mechanism reveals the toxicity of biogenic synthesized AgNPs. Adverse effects on oxidative stress were probably related to the histopathological damage of its vital organs like gill, liver, and muscle. Finally, the fish treated with biogenic synthesized AgNPs were significantly (p < 0.05) downregulates the oxidative stress genes such as Cu-Zn SOD, CAT, GPx1a, GST-α, CYP1A, and Nrf-2 expression patterns. The present study provides evidence of biogenic synthesized AgNPs influence on the aquatic life through induction of oxidative stress.

Synthesis of Quercetin Functionalized Silver Nanoparticles and Their Application for the Colorimetric Detection of L‐Cysteine in Biologically Complex Fluids

AbstractIn the present manuscript authors report an eco‐friendly, simple, and cost‐effective one‐pot synthesis of quercetin functionalized silver nanoparticles (Q‐AgNPs). The synthesized Q‐AgNPs exhibited surface plasmonic resonance absorption band at 418 nm which confirmed the synthesis. The synthesized Q‐AgNPs were further characterized by X‐ray diffraction which confirmed the crystalline structure of Q‐AgNPs. FTIR analysis of Q‐AgNPs was performed to find out the functional groups present on Q‐AgNPs. The distribution, size, and morphology of Q‐AgNPs were determined through scanning electron microscopy (SEM), transmission electron microscopy (TEM), and dynamic light scattering (DLS) analysis. SEM, TEM, and DLS analysis revealed that synthesised nanoparticles were spherical in morphology with an average size of 40 nm. Furthermore, the synthesised Q‐AgNPs were observed to selectively sense cysteine in water, urine, and foetal bovine serum with detection limit of 21.1 nM, 86 nM, and 230 nM respectively. The SEM, TEM, and DLS analysis clearly indicated the aggregation of Q‐AgNPs in the presence of l‐cysteine particles as compared to the control Q‐AgNPs (without l‐cysteine). The findings revealed that synthesized Q‐AgNPs can be utilized to detect low concentration of cysteine in water and biological complex fluids without any requirement of sophisticated instrumentation.

Bacitracin and isothiocyanate functionalized silver nanoparticles for synergistic and broad spectrum antibacterial and antibiofilm activity with selective toxicity to bacteria over mammalian cells

Silver nanoparticles functionalized with bacitracin (BA), a cyclic peptide and isothiocyanate (ITC), a natural plant product, was fabricated. The particle size of AgNP-BA&ITC was optimized using full factorial design. The optimized particles were of 10–15 nm in size as seen under TEM and showed chemical signature of both bacitracin as well as isothiocynate in FTIR spectroscopy. XRD analysis confirmed the crystalline nature of these particles. Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) showed 21 mg/g silver content in AgNP-BA &ITC. These nanoparticles exhibited MIC in the range of 12.5–25 μg/mL and > 3 log10 reduction in cell viability for both Gram positive and Gram-negative bacteria. They clearly demonstrated biofilm inhibition (BIC90 = 150–400 μg/mL) as well as were capable of eradicating both young and mature preformed biofilms as observed by live/dead imaging and crystal violet assay. Further cytotoxicity assay suggests high selectivity (IC50/MIC90 value = 15.2–30.4) of these particles. The results in the present investigation provide role of these novel nanoparticles having substantially low silver content with reduced toxicity and good antibacterial and antibiofilm activity for external wound healing applications.

Effects of wound dressing based on the combination of silver@curcumin nanoparticles and electrospun chitosan nanofibers on wound healing

ABSTRACT Healing of various skin wounds is a lengthy process and often combined with bacterial infection and scar formation. Biomimetic electrospun nanofibrous wound dressing loaded with materials that possess properties of dual antibacterial and tissue repair would be developed to address this problem. In this study, a composite chitosan electrospun nanofibrous material containing Cur@β-CD/AgNPs nanoparticles composed of silver and curcumin possessed synergic effects on antibacterial activity and wound healing. The developed functionalized silver nanoparticles showed effective activity against both Gram-negative and Gram-positive bacteria. In vivo, Cur@β-CD/AgNPs chitosan dressing displayed enhanced wound closure rates compared to commercial AquacelAg. Moreover, Cur@β-CD/AgNPs chitosan dressing contributed to the most uniform collagen distribution by Masson’s trichrome staining. In brief, Cur@β-CD/AgNPs chitosan nanofibers work as a potential wound dressing with antibacterial and antiscarring properties.

Synthesis and Characterization of Functionalized Silver Nanoparticles for Selective Screening of Mercury (II) Ions

Synthesis and Characterization of Functionalized Silver Nanoparticles for Selective Screening of Mercury (II) Ions

Multi-Functional Silver Nanoparticles for High-Throughput Endospore Sensing.

In spore-forming bacteria such as Bacillus and Clostridium, the vegetative cells form highly durable hard shells called endospores inside the bacteria to survive as the growth environment deteriorates. Because of these properties, endospores can cause food poisoning and medical accidents if they contaminate food, medicine, or other products, and it is required for technology to detect the spores at the manufacturing site. In this study, we focused on the surface-enhanced Raman scattering (SERS) method for the sensitive detection of dipicolinic acid (DPA), a molecular marker of endospores. We constructed Fe3O4/Ag core–shell functional silver nanoparticles that specifically bind to DPA, and investigated a method for the qualitative detection of DPA by SERS and the quantitative detection of DPA by fluorescence method using a terbium complex formed on the surface. As a result, the concentration of the functional silver nanoparticles constructed could detect spore-derived DPA by fluorescence detection method, and SERS was several tens of nM. The functionalized nanoparticles can detect DPA quantitatively and qualitatively, and are expected to be applied to detection technology in the production of food and pharmaceuticals.

Electrochemical sensing of biotin-avidin interaction on gold electrode modified by silver nanoparticles through covalent co-assembling

Electrochemical sensing of biotin-avidin interaction was investigated on gold electrode modified with 3-mercaptopropanoic acid (MPA) successively co-assembled with cysteamine functionalized silver nanoparticles and biotin or avidin. The stable aqueous colloid of cysteamine functionalized silver nanoparticles was synthesized successfully by well-known citric acid reduction method. Gold electrode was first modified with a monolayer of MPA by self-assembly technique. Then, cysteamine functionalized silver nanoparticles and biotin or avidin was co-assembled on the MPA modified gold electrode through an amide linkage. The stepwise modification process was optimized in terms of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurement in [Fe (CN)6]3−/4− redox system by varying the ratio of functionalized silver nanoparticles and biotin or avidin, viz., 1:2, 1:1, 2:1. Based on obtained results, the electrochemical sensing performances of 1:1 silver nanoparticle and biotin or avidin co-assembled gold electrode was performed by CV and EIS for varying concentration of complementary bio-affinity molecules in the same redox system. Both the CV and EIS measurements were found to have good response by resistive and capacitive changes due to coupling with a complementary biomolecule on co-assembled gold electrode. The use of avidin assembled gold electrode had led to much better response towards varying concentration of biotin over that of the biotin assembled gold electrode towards avidin.

Highly sensitive electrochemical detection of biotin-avidin interaction on gold electrode modified with silver nanoparticles through bilayer assembly

The trifunctional l-cysteine containing carboxylic acid, amine and thiol is chemisorbed on the gold electrode surface via the thiol groups to form the self-assembled monolayer. Then the bilayer is assembled stepwise on the cysteine modified gold electrode. A layer of 3-marcaptopropionic acid functionalized silver nanoparticles is covalently coupled with amine group of cysteine and other layer of amine functional group containing biotin or avidin molecules is covalently coupled with carboxylic acid functional groups of cysteine. The improvement of electrochemical properties are noted for the cysteine modified gold electrode coupled with biomolecules first followed by coupling with the functionalized silver nanoparticles. This modified gold electrode is used to study the electrochemical sensing response of respective complementary biomolecule immobilized gold electrode towards the biotin or avidin. As revealed the avidin modified electrode is found to have better sensing performances toward biotin in terms of sensitivity and detection limit over the other one. The sensitivity of 1.243 Ω (ng)-1 L mm-2 and detection limit of 1.4 × 10−3 ng/L is observed for avidin sensing on biotin layer. For biotin sensing on avidin layer a sensitivity of 6.143 Ω (ng)-1 L mm-2 and detection limit of 1.2 × 10−5 ng/L is obtained from the calibration plot.

A novel approach for on-site screening of organophosphorus nerve agents based on DTNB modified AgNPs using surface-enhanced Raman spectrometry.

Organophosphorus nerve agents (OPNAs), such as Sarin (GB), Tabun (GA), Soman (GD) and VX, would cause tremendous harm in military and terrorist attacks, and thus the development of simple methods for the rapid and efficient detection of these hazardous substances is of great necessity. Herein, we present a novel approach for the facile, rapid and sensitive detection of real OPNAs. The detection substrate is fabricated using functionalized silver nanoparticles (AgNPs) immobilized with acetylcholinesterase (AChE) and 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB). In the absence of OPs, AChE catalyzes the hydrolysis of acetylthiocholine (ATCh) to form thiocholine (TCh), which continues to interact quickly with DTNB to produce a very sensitive Raman probing molecule, TNB. The inhibition of the activity of AChE by OPs could induce an obvious decrease of characteristic Raman peaks of 5-thio-2-nitrobenzoic acid (TNB) at 1335 cm-1. The introduction of DTNB as an enzyme activity indicator significantly improves the detection sensitivity with distinct characteristic Raman peaks. The LOD of GD, which is one of the most easily aged OPNAs, could reach 0.1 nM due to its strongest inhibition of AChE. Moreover, various OPNAs exhibit different SERS intensities due to their different inhibition capacities of AChE. Hence, the new strategy has great potential in public security early warning and environmental analysis.