Highly catalytic nanoenzyme of covalent organic framework loaded starch- surface-enhanced Raman scattering/absorption bi-mode peptide as biosensor for ultratrace determination of cadmium

Abstract

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.

Research Progress on the Application of Covalent Organic Framework Nanozymes in Analytical Chemistry

“…When it enters the human body, it can cause heavy metal poisoning and threaten human health. Li et al [92] prepared a soluble starchloaded COF (COFTpBD-SS) nanozyme and then controlled its catalytic ability through peptides to construct a SERS sensor to detect 0.025-0.95 nmol/L Cd 2+ in rice. From the currently reported applications of COF nanozymes in food analysis, it can be seen that using COFs as a carrier to load nanoparticles has broad application prospects.…”

Detection of Cadmium(II) in Aquatic Products Using a Rolling-Circle Amplification-Coupled Ratio Fluorescent Probe Based on an Aptamer–Peptide Conjugate

“…In recent years, fluorescence, 15 colorimetric, 16 Raman, 17 and other methods based on biosensors have been increasingly applied to the detection of Cd 2+ . For example, Gan et al 18 designed a colorimetric method based on aptamer-functionalized gold nanoparticles (AuNPs) to achieve specific recognition of Cd 2+ with a detection limit of 1.12 μg/L.…”