PdPt nanoparticles anchored on the N-G with the integration of PANI nanohybrids as novel redox probe and catalyst for the detection of rs1801177

Single nucleotide polymorphism (SNP) in lipoprotein lipase (LPL) gene (rs1801177) is strongly associated with the increased progression of atherosclerosis, threatening global public health. In this work, a relatively simple, specific and ultrasensitive electrochemical DNA biosensor was constructed to detect rs1801177 for the first time. A glass carbon electrode was modified with fullerene (C60)/polyamidoamine (PAMAM)/gold (Au) nanoparticles nanocomposites film. In addition the nitrogen-doped graphene (N-G)/palladium platinum (PdPt) bimetallic nanoparticle/ polyaniline (PANI) nanohybrids were synthesised and used to label the signal probes. These nanohybrids have abundant active groups, and efficient redox and catalytic activity, allowing them to be used as the nanocarrier for a redox nanoprobe without the additional modification of electroactive substance and catalyst, which could effectively simplify the operation procedure and shorten the analysis time. With the catalysis of H2O2 by nanohybrids, the detection signal of N-G/PdPt/PANI itself could be significantly enhanced, lead to the improvement of the sensitivity. Under optimal conditions, the electrochemical DNA biosensor exhibited desirable performance for the determination of rs1801177 with a wide linearity ranging from 10 fM to 10 nM and a relatively low detection limit of 3.33 fM (S/N=3). The proposed biosensor showed excellent selectivity to the target DNA compared to possible interfering substances. The results suggested that this method has potential applications in clinical research.