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 long-spined sea urchin-like morphology (Pt-LSSUs@PAA) was synthesised by a simple chemical method for the construction of nano-sensing interface. Ru(NH3)63+ is used as a primary electron acceptor that is electrostatically attracted to peptide nucleic acid modified electrodes and Fe(CN)63？ is introduced into the redox system as secondary electron acceptor to regenerate Ru3+ 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？=？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