Highly sensitive electrochemical peptide-based biosensor for marine biotoxin detection using a bimetallic platinum and ruthenium nanoparticle-tethered metal-organic framework modified electrode

Saxitoxin (STX) is a highly toxic small-molecule cyanotoxin that is water-soluble, stable in acidic media, and thermostable. STX is hazardous to human health and the environment in ocean, thus it is an important to detect it at very low concentrations. Herein, we developed an electrochemical peptide-based biosensor for the trace detection of STX in different sample matrix utilizing differential pulse voltammetry (DPV) signal. We synthesized the nanocomposite of zeolitic imidazolate framework-67 (ZIF-67) decorated bimetallic platinum (Pt) and ruthenium (Ru) nanoparticles (Pt-Ru@C/ZIF-67) using impregnation method. The nanocomposite modified with screen-printed electrode (SPE) was subsequently used to detect STX in the range of 1-1,000 ng mL-1, with a detection limit (LOD) of 26.7 pg mL-1. The developed peptide-based biosensor is highly selective and sensitive towards STX detection, thus it represents a promising strategy for the development of novel portable bioassay for monitoring various hazardous molecules in aquatic food chains.

Automated summary

A peptide-based biosensor was developed for the trace detection of Saxitoxin (STX) in the ocean. The biosensor utilized differential pulse voltammetry (DPV) signal and a nanocomposite of zeolitic imidazolate framework-67 (ZIF-67) decorated with bimetallic platinum (Pt) and ruthenium (Ru) nanoparticles (Pt-Ru@C/ZIF-67). The biosensor showed high selectivity and sensitivity towards STX detection with a detection limit of 26.7 pg mL-1, and it represents a promising strategy for monitoring hazardous molecules in aquatic food chains.