Novel potential and current type chiral amino acids biosensor based on L/D-handed double helix carbon nanotubes@polypyrrole@Au nanoparticles@L/D-cysteine

Novel chiral amino acids biosensor based on both potential difference and current ratio simultaneously was first established by employing left/right-handed double helix carbon nanotubes (L/D-DHCNT) with chiral structure as substrate material, and by self-assembly anchoring L/D-cysteine (L/D-Cys) on the surface of the left/right-handed double helix carbon nanotubes@Polypyrrole@Au nanoparticles nanocomposites (L/D-DHCNT@PPy@AuNPs). In this work, L/D-DHCNT@PPy@AuNPs@L/D-Cys was successfully constructed via a facile and environment-friendly process. Interestingly, in order to obtain highly dispersed AuNPs deposited on L/D-DHCNT, polypyrrole polymerized from pyrrole acts as a locating agent. Owing to the combination of unique performance of the L/D-Cys and L/D-DHCNT with chiral structure, and PPy and AuNPs with outstanding conductivity, an extremely efficient electrochemical chiral biosensing system was constructed that exhibited enhanced conductivity, sensitivity and chiral recognition capacity for tyrosine (Tyr), tryptophan (Trp) and glutamic acids (Glu) enantiomers. Utilizing both the potential difference and current ratio signal to commendably realize the electrochemical recognition and quantitative determination of amino acid enantiomers in their racemic solution. In addition, achieving the detection of Tyr in tablet samples by fabricated ultra-efficient electrochemical chiral biosensing system. Therefore, L/D-DHCNT@PPy@AuNPs@L/D-Cys as novel and ultrasensitive chiral biosensing system possesses the capability of chiral recognition of amino acid enantiomers, and it opens up the potential application of L/D-DHCNT@PPy@AuNPs@L/D-Cys in the field of chiral biosensors.