Ultrasensitive electrocatalytic detection of COX-2 rs20417: relying on 3D interconnected architecture of Pt-LSSUs@PAA nanostructures for sensor interface modification

Abstract

Mutated COX-2 has become the new molecular marker of aspirin resistance. However, there is still a technical 'bottleneck' for direct and sensitive detection of circulating COX-2 mutant gene. In this work, we reported a simple and ultrasensitive electrochemical method for COX-2-765G/C (rs20417) detection for the first time. Polyallylamine (PAA) functionalised Pt nanostructures with longspined sea urchin-like morphology (Pt-LSSUs@PAA) was synthesised by a simple chemical method for the construction of nanosensing interface. Ru(NH 3) 6 3þ is used as a primary electron acceptor that is electrostatically attracted to peptide nucleic acid modified electrodes and Fe(CN) 6 3À is introduced into the redox system as secondary electron acceptor to regenerate Ru 3þ after electrochemical reduction for multiple redox cycles. Different pulse voltammetry was applied to record the electrochemical signals. Under optimal conditions, the DNA sensors showed a wide linear relationship, from 10 fM to 1 nM, with detection limits of 3.3 fM (S/N ¼ 3). This study will provide the basis for the precise use of aspirin, and it has important guiding value for individual drug testing of cardiovascular disease.