A novel electrochemical aptasensor for L-tryptophan detection utilizing photoluminescent covalent organic polymer

A novel method was developed for the sensitive detection of L-tryptophan (Trp) utilizing an imine-linked covalent organic polymer (COP) with inherent photoluminescent properties. The COP was synthesized through the reaction of aminoclay (AC) with terephthalaldehyde (TPA). This COP incorporates building blocks featuring a large conjugated aromatic skeleton, high stability, a rough surface, and uniform morphology, facilitating effective binding with aptamers. Electrochemical testing results demonstrated that the aptasensor based on the COP significantly enhanced the detection of Trp, achieving an exceptionally low detection limit of 0.03 fM within a Trp concentration range of 0.1 fM to 500 nM. This detection limit surpasses those of most other reported Trp sensors. Furthermore, the aptamer-based biosensor exhibited remarkable stability and repeatability. This study introduces a new electrochemical sensing approach for Trp detection based on the COP, showcasing a comprehensive understanding of COP-based biosensor design that can be extended to detect various target compounds. The proposed method presents an innovative and cost-effective solution for the swift and accurate identification of Trp using the COP.