Using copper nanoclusters (CuNC) and polyvinylidene fluoride-co-hexafluoropropylene (PVH) as the matrix respectively, pymetrozine (PYM) as the template molecule and methyl acrylate (MAA) as the functional monomer, two new surface molecularly imprinted polymer nanoprobes (CuNC@MIP/PVH@MIP) with recognition and three nanocatalytic functions were prepared. The nanoprobes were characterized by molecular spectroscopy, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). It was found that these two nanoprobes could catalyze the sodium lactate (NaL)-HAuCl4 reaction to form indicator gold nanoparticles (AuNPs) with surface enhanced Raman scattering (SERS) activity. Under ultrasonic irradiation, the indicator reaction was further promoted due to the piezoelectric and triboelectric effects. Combined the piezoelectric nanogenerator (PENG) with triboelectric nanogenerator (TENG) in water phase, the strongest catalysis was achieved with two nanoprobes. The catalysis was evaluated using the slope procedure, and mainly comes from the TENG. Upon addition of PYM, the catalysis further enhanced. Therefore, a new, highly sensitive and selective SERS analysis platform for PYM in foods was established, with a linear range of 0.05-1.2 nmol/L and a detection limit of 0.016 nmol/L PYM.

The triboelectric nanogenerator (TENG) is an innovative energy harvesting technology. There are no reports two nanoprobes TENG in liquid phase for nanosol surface enhanced Raman scattering/absorption (SERS/Abs) quantitative analysis. In this article, two new surface molecular imprinted polymer (SMIP) nanocatalytic probes were synthesized using Cu single atom catalyst (CuSAC) and polyethylene glycol 10,000 (PEG10000) as nanosubstrates respectively and 4-methylimidazole (MI) as the template. It was found that these two nanoprobes not only recognize MI but also catalyze the HAuCl4-mandelic acid (MA) indicator reaction. The in situ generation of gold nanoparticles (AuNP) exhibit SERS and surface plasmonic resonance (SPR) Abs effects. Under the ultrasonic irradiation, a nanoscale TENG constructed with CuSAC@MIP as the positive electrode and PEG10000@MIP as the negative electrode. Which exhibit the strongest catalytic effect. After adding MI, the catalysis enhanced greatly, and 0.05-0.3 nmol/L MI and 0.1-1.0 nmol/L can be determined by SERS/Abs dual-mode method. In addition, the ultrasonic driven TENG catalytic mechanism was proposed.

Silver nanoclusters (AgNC) and polytetrafluoroethylene (PTFE) were employed as the nanomatrix of positive and negative electrodes respectively, ammonium pentadecafluorooctanoate (APO) as the template molecule, and trialdehyde resorcinol (Tp) and biphenylamine (BD) as functional monomers to synthesize two new surface molecularly imprinted covalent organic framework nanoprobes (MCOFP and MCOFN). The slope procedure was used to evaluate the catalysis of those nanoprobes for the gold nanoparticle (AuNP) reaction of sodium formate (SF)-HAuCl₄ with surface-enhanced Raman scattering (SERS) monitoring. The piezoelectric nanocatalysis of MCOFP was observed firstly. The mixture of two probes exhibited molecular recognition, nanocatalytic, piezoelectric nanocatalysis and triboelectric nanogenerator tetra-functions. Upon addition of APO, the catalytic performance of the mixture system was further enhanced, mainly due to TENG amplification. Based on these findings, a new TENG-based SERS quantitative analytical method was developed for trace detection of 0.05–0.50 nmol/L APO.

A silica surface molecularly imprinted covalent organic framework piezoelectric nanocatalytic nanoprobe (SiO2@COF) with nanocatalytic, piezoelectric nanocatalytic and specific recognition of bisphenol A (BPA) functionality was prepared by using silica (SiO2) as nanosubstrate, 1,3,5-tris(4-aminophenyl) benzene (Tb) and 2,5-dimethoxy-1,4-dicarboxaldehyde (Dt) as functional monomers, and BPA as template molecule. The SiO2@TbDt probe was characterized in detail by transmission electron microscope, atomic force microscope and X-ray photoelectron spectroscopy. It efficiently catalyzed H2O2 oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) to produce the oxidized product TMBox, a molecular probe indicator with surface-enhanced Raman scattering (SERS) activity at 1605 cm(-1) in the presence of silver nanosol substrate. Under the ultrasound irradiation, the SiO2@TbDt showed superb catalytic activity, which was increased by 777 %. Based on the recognition reaction of SiO2@TbDt-BPA and its inhibition of the nanocatalytic activity, a new liquid-phase ultrasonic piezoelectric nanoprobe-SERS quantitative analysis strategy for the determination of BPA was constructed with a linear range of 1.0-15 nmol/L BPA and the limit of detection (LOD) of 0.35 nmol/L BPA. The SiO2@TbDt ultrasonic piezoelectric nanocatalytic enhancement mechanism and a slope ratio procedure for rapid screening and evaluation of piezoelectric nanocatalytic nanoprobe were constructed.

Glyphosate (Gly) is a widely used herbicide, if Gly is exposed for a long time, it will cause a major threat to public health. Therefore, it is urgently needed to develop a highly sensitive and highly specific method for Gly. In this paper, a new AuNP surface molecularly imprinted polymer probe (AuNP@MIP) was synthesized for specific recognition of Gly, using gold nanoparticles (AuNP) as substrate, Gly as template, acrylamide (AM) as monomer. The probe was characterized in detail, which exhibited a strong resonance Rayleigh scattering (RRS) peak at 370 nm. The RRS-energy transfer (RRS-ET) effect was enhanced with increasing concentration of Gly, and the RRS signal at 370 nm was decreased linearly with 2.5-37.5 nmol/L Gly, with a detection limit of 1.9 nmol/L. The effect of AuNP sizes on the nanoprobes was investigated for Gly specific recognition. The method was used for the determination of Gly in water samples with the relative standard deviation (RSD) of 0.4-3.2 % and the recovery of 94.2-104.9 %.

Utilizing 1,3,5-triformylphloroglucinol (Tp) and tetramethylbenzidine (TMB) as functional monomers, nano Fe3O4 as the substrate, and 2,4,6-trichlorophenol (TCP) as the model molecule, a Schiff-base bond-based covalent organic framework nanoprobe (Fe3O4@COF) with specific recognition capability for TCP was synthesized through a microwave-assisted procedure. The nanoprobe was characterized through a comprehensive suite of techniques, including absorption spectroscopy, resonance Rayleigh scattering (RRS), Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and zeta potential analysis. It exhibited a significant RRS peak at a wavelength of 510 nm. As the concentration of TCP increased, the resonance Rayleigh scattering energy transfer (RRS-ET) effect was intensified, leading to a decrease in the RRS signal intensity detected at 510 nm. The magnetic separation enrichment procedure demonstrates a linear response varying between 0.0025 and 0.05 μmol/L, with a detection limit (LOD) of 0.0016 μmol/L for TCP. Leveraging these characteristics, we developed an RRS-ET method that enables rapid, simple, selective, and sensitive detection of TCP.

A new nanosurface molecularly imprinted polyacrylamide nanoprobe (Fe3O4@MIPB) for pH sensing was prepared by using Fe3O4 magnetic nanoparticles as a substrate, rhodamine B (RhB) as a template and sensing molecule, acrylamide (AM) as a functional monomer, and ethylene glycol dimethacrylate (EGDMA) as a cross-linker. The nanoprobe was characterized by scanning electron microscopy (SEM), hysteresis loop, Fourier transform infrared spectroscopy (FT-IR), and resonance Rayleigh scattering (RRS) spectroscopy. Fe3O4@MIPB exhibited a strong RRS peak at 375 nm, and the sensing molecule RhB as the acceptor was enhanced with increasing pH in the pH range of 2.2-6.2, which enhanced the RRS-ET effect, resulting in a linear decrease in the RRS intensity at 375 nm. In the pH range of 7.0-9.8, the RRS intensity at 375 nm decreased linearly with increasing pH. Accordingly, a novel pH sensor platform was constructed for the detection of pH in Li River water samples and food samples, with relative standard deviations (RSDs) of 0.43-1.4 and 0.28-4.1%, respectively. In this study, a novel RhB-imprinted magnetic molecularly imprinted polymer was prepared, and it was combined with the RRS method to detect pH for the first time. High sensitivity, a wide pH detection range, and excellent selectivity and stability in complex matrices were demonstrated.

Sulfadimethoxine (SDM), an emerging contaminant, poses significant risks to the environment and human health, necessitating selective and sensitive detection methods. This study synthesized highly catalytic palladium nanoclusters (PdNCs) using methionine as a stabilizer and ascorbic acid as a reducing agent. A polyaniline core-shell structured surface molecularly imprinted polymer nanoprobe (PdNCs@MIP-Apt) was prepared using PdNCs as the core, SDM as the template, and aptamer (Apt) as second recognition element. The PdNCs@MIP-Apt nanoprobes exhibit dual recognition of SDM and strong catalytic activity for the Au(III)-HPO32- nanogold (AuNP) indicator reaction, generating AuNPs with strong resonance Rayleigh scattering (RRS) at 370 nm. Under ultrasonic irradiation, the nanoprobe showed high sensitivity, with a detection limit of 0.7 nmol/L SDM. The dual recognition was provided lower detection limits and better selectivity than the single recognition. Applied to milk, the method achieved Relative Standard Deviations (RSD) of 0.90-3.8 % and recoveries of 96.8-106 %.

A nanomagnetic surface molecularly imprinted silica probe (Fe3O4@MIP) was prepared through the sol-gel method, using nano iron tetroxide (Fe3O4) as a substrate. Phenol (PN) taken as template molecule, 3 - aminopropyltriethoxysilane (APTES) as functional monomer, ethyl orthosilicate (TEOS) as cross - linking agent and aqua ammonia as an initiator. It was characterized in detail. The nanoprobe exhibited a significant resonance Rayleigh scattering (RRS) effect at 370 nm and specifically recognized PN. In the presence of 4-aminoantipyrine (4-APP), with the PN concentration increased, RRS - energy transfer (RRS-ET) was enhanced. The RRS signal intensity decreased at 370 nm, and the linear determination range was 2.5-50.0 nmol/L PN, with a limit of detection (LOD) reaching 2.1 nmol/L. Therefore, a novel, fast, sensitive and selective RRS-ET method for determination of trace PN was developed. The method was used to detect PN in water samples with a relative standard deviation (RSD) from 1.4 to 8.3 % and a recovery rate from 92.0 to 110.0 %.

In this paper, gold nanocluster (AuNC) was prepared by reduction of HAuCl4 with Csy-Pro-Pro-Cys-Trp-NH2 polypeptide (PT). Using AuNC as substrate, Cd2+ as template ions and acrylic acid as monomers, a dual recognition ion-imprinted polymer-PT nanocatalytic probe (AuNC@MIPPT) was fabricated. It was characterized by Fourier Transform Infrared Spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Zeta potential analyzer. It was found that the nanocatalytic probe not only recognized Cd2+, but also catalyzed the reduction of sodium hypophosphite (SH) to generate more gold nanoparticles (AuNPs). Using Victoria blue (VBB) as the molecular probe, the product AuNPs of sodium hypophosphite-HAuCl4 reaction generated a strongest surface enhanced Raman scattering (SERS) peak at 1615 cm-1. When Cd2+ was present, the PT and imprinted sites on the surface of the nanocatalytic probe had a specific recognition effect on Cd2+, and the SERS signal of the system linearly decreased. The decreased SERS signal values were linear to the concentration of Cd2+ in the range of 0.03-0.88 nmol/L, with a detection limit of 0.023 nmol/L, and the recovery of 99.83 % to 107.89 %.

A nanosurface molecularly imprinted polyacrylamide nanoprobe (GO@MIP) with recognition, nanocatalysis and piezoelectric nanocatalysis was prepared by sol-gel method with nano graphene oxide (GO) as matrix, 2,4-dichlorophenoxyacetic acid (2,4-D) as template molecule and acrylamide (AM) as functional monomer. The probe was characterized by molecular spectroscopy, transmission electron microscopy and X-ray electron spectroscopy. Using the slope ratio procedure, the nanocatalysis of acrylic acid-HAuCl4 nanoreaction was studied by surface-enhanced Raman scattering (SRES) technique with the generated gold nanoparticles (AuNPs) as indicator and substrate. Under the ultrasonic irradiation, the strong piezoelectric catalysis was found firstly, the nanocatalysis activity enhanced by 123 %. Upon addition of 2,4-D, the conjugate of GO@MIP-2,4-D exhibits stronger catalysis, and its SERS signal is linearly enhanced. Accordingly, a new GO@MIP piezoelectric nanocatalytic probe was fabricated for SERS determination of 0.001-0.015 nmol/L 2,4-D, with a detection limit of 0.068 pmol/L, relative standard deviation of 1.19 % ∼ 6.00 % and the recovery of 92.0-108.0 %.

A new magnetic-liquid crystal nanosurface molecularly imprinted polymer (5CB-Fe3O4@MIP) resonance Rayleigh scattering temperature sensor was prepared, using liquid crystal 4'-cyano-4'-pentylbiphenyl as the temperature sensing element, nano-Fe3O4 as the substrate, methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the crosslinking agent. It was characterized by molecular spectroscopy, scanning electron microscopy and Fourier transform infrared spectroscopy. The thermosensitive effect of 11 liquid crystals, that is, the relationship between RRS and temperature, was studied. The 4'-cyano-4'-pentylbiphenyl exhibits best sensitive. The 5CB-Fe3O4@MIP temperature sensor had a strong resonance Rayleigh scattering peak at 370 nm. The resonance Rayleigh scattering intensity increased with the increase of temperature, and showed a good linear relationship. The temperature range of measurement was 30-95 °C, with a slope of 16.8 a.u./°C. And by optimizing the preparation conditions of molecularly imprinted polymers, the best preparation conditions were obtained: template molecule: 0.25 mmol, functional monomer: 2.5 mmol, cross-linker: 5 mmol, reaction temperature: 70 °C, reaction time: 2.5 h. As a comparison, we also studied the effect of Fe3O4 with different particle sizes on the 5CB-Fe3O4@MIP temperature sensor. At the same time, the temperature sensor is applied to the temperature measurement of cooling water, which is effective.

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, alpha-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.

Although gold nanoparticle (AuNP) surface molecularly imprinted polymers (Au@MIP) were not fresh, this is of interest to spectral analysts due to their possession of high affinity for the target molecules, strong nanocatalysis to amplify the signals, and good stability to obtain accuracy. New avenues of molecular spectroscopy with straightforward, sensitivity and selectivity can be established using Au@MIP nanosol. In this article, a new carbendazim (CAR) Au@MIP nanocatalytic probe was prepared and the new Au@MIP-CAR-HAuCl4-vanillin (VAN) nano indicator reaction was constructed with in situ-generated AuNP as indicator, which with surface enhanced Raman scattering (SERS), resonance Rayleigh scattering (RRS) and absorption (Abs) effects. Due to space constraints, these imprinted points show high selectivity in the recognition of CAR whose size and shape correspond to the template. The Au@MIP was sensitively detected CAR using SERS/RRS/Abs techniques, with determination range of 0.1-10, 1.5-17.5 and 9.0-30.0 nmol/L, the detection limits of 0.08, 1.0 and 5.0 nmol/L CAR respectively. In addition, the nanocatalytic mechanism was studied.

Nanoclusters have strong catalytic effect, but their stability was poor. Biomolecule functionalized gold nanoclusters (AuNC) have attracted extensive attention due to their good biocompatibility, stable physicochemical properties and strong catalytic activity. In this study, the peptide (PT) was used as a template to synthesize the PTAuNC nanoprobe with recognition and catalysis. The results show that PTAuNC has a strong catalytic effect on the indicator reaction of 3,3 ',5,5 '-tetramethylbenzidine (TMB)-H2O2 to produce the oxidized TMB (TMBox). The TMBox had a strongest fluorescence (FL) peak at 410 nm and an absorption peak at 650 nm. Addition of nanosilver (AgNPs), it produced a strong surface enhanced Raman scattering (SERS) peak at 1616 cm(-1) and a resonance Rayleigh scattering (RRS) peak at 370 nm. The new nanocatalytic indicator reaction was organically coupled with the PTAuNC-Al3+ recognition reaction, and a PTAuNC catalytic amplification SERS/RRS/FL/Abs tetramode biosensor platform for Al3+ was constructed. The Al3+ concentration in the range of 0.5-60 nmol/L had a good linear relationship with SERS intensity, with detection limit of 0.21 nmol/L. The method has been applied to the determination of Al3+ in water and food samples. The recovery and relative standard deviation (RSD) were 92.4-109.8% and 1.2-9.8%, respectively.

Terbium metal-organic framework (TbMOF) was prepared by microwave method with 1,3,5-benzenetricarboxylic acid as ligand. With HAuCl4 as precursor and NaBH4 as reducing agent, TbMOF-loaded gold nanoparticles (AuNPs) catalyst (TbMOF@Au1) was prepared rapidly and characterized by transmission electron microscope (TEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. It was found that TbMOF@Au1 has a strong catalytic effect on the HAuCl4-Cys nanoreaction, and the produced AuNPs have a strong resonant Rayleigh scattering (RRS) peak and surface plasmon resonance absorption (Abs) peak at 370 nm and 550 nm, respectively. With the addition of the molecular probe Victoria blue 4R (VB4r), AuNPs have a strong surface-enhanced Raman scattering (SERS) effect, the target analyte molecules are trapped in between the nanoparticles and a hot spot effect created in the process resulting in an extremely high SERS signal. A new SERS/RRS/Abs triple-mode analysis method for Malathion (MAL) was established by coupling this new TbMOF@Au1 catalytic indicator reaction with MAL aptamer (Apt) reaction, and its SERS detection limit was 0.21 ng/mL. The SERS quantitative analysis method has been applied to the analysis of fruit samples with the recovery of 92.6-106.6 % and the precision of 2.72-8.16 %.

A new covalent organic framework loaded gold nanocluster (AuCOF) was prepared by solvothermal procedure, using 1,3,5-benzenetricarboxaldehydeand p-phenylenediamine and chloroauric acid as precursor. It was found that the AuCOF exhibits strong catalysis of sulfite reduction of HAuCl4 to form gold nanoparticles (AuNP) with surface enhanced Raman scattering (SERS) and resonance Rayleigh scattering (RRS) effects. The aptamer (Apt) of estradiol (E2) can be electrostatically adsorbed on the AuCOF surface to suppress its catalytic performance. While the AptE2 can selectively bind to target molecule E2 and desorb from the AuCOF surface to recover its catalysis. The SERS and RRS signals increased linearly with E2 concentration increasing due to produce more AuNP indicator. The highly sensitive SERS method shows good linearity with E2 concentration in the range of 0.333-5.33nmol/L, and the detection limit was 0.150 nmol/L E2. This SERS method has been used for the determination of E2 in actual samples. In addition, the nanocatalytic mechanism and SERS quantitative analysis formula were studied.

Liquid crystals (LCs) are a very important display material. However, the use of LC, especially LC-loaded nanoparticles, as a catalyst to amplify the analytical signal and coupled with specific aptamer (Apt) as a recognition element to construct a highly sensitive and selective three-mode molecular spectral assay is rarely reported. In this article, five LCs, such as cholesteryl benzoate (CB), were studied by molecular spectroscopy to indicate the liquid crystal nanoparticles in the system, and highly catalytic and stable CB loaded-nanosilver (CB@AgNPs) sol was prepared. The slope procedure was used to study the catalysis of the five LCs and CB@AgNPs on the new indicator reaction between AgNO3 and sodium formate (Fo) to produce silver nanoparticles (AgNPs) with a strong surface plasmon resonance absorption (Abs) peak at 450 nm, a resonance Rayleigh scattering (RRS) peak at 370 nm and a surface enhanced Raman scattering (SERS) peak at 1618 cm−1 in the presence of molecular probes. By coupling the new CB@AgNPs catalytic indicator reaction with the Apt reaction, a new CB@AgNPs catalytic amplification-SERS/RRS/Abs trimode biosensoring platform was constructed for detecting inorganic pollutants, such as Pb2+, Cd2+, Hg2+ and As3+.

High affinity peptides (PTs) have been used in nanoanalysis, but there are no reports which combine PTs with a liquid crystal (LC) covalent organic framework (COF) supported soluble starch (SS) catalytic amplification system as a biosensor recognition element. In this study, a new, highly sensitive and selective bi-mode molecular biosensor has been developed for the determination of cadmium ion (Cd2+). Specifically, a highly catalytic and stable COF supported SS nanosol catalyst was fabricated such that a nanocatalytic indicator reaction system for HAuCl4-sodium formate was established based on surface-enhanced Raman scattering (SERS). The Au nanoparticles produced exhibited a surface plasmon resonance (SPR) absorption peak at 535 nm and a SERS peak at 1,615 cm-1. Combining the nanocatalytic amplification indicator system with the specific PTs reaction permitted a sensitive and selective SERS/absorption bi-mode platform to be developed for the determination of cadmium in rice. The linear range for SERS determination was 0.025-0.95 nmol/L and the detection limit (DL) was 0.012 nmol/L.