A new strategy for effectively improving sensitivity of amperometric biosensor based on dual-signal synergistic effect has been developed. Reduced graphene oxide-Au-poly(methylene blue) (rGO-Au-PMB) as a novel redox species with strong current signal at −0.18 V was synthesized by one-step method and used to fabricate the substrate of the biosensor. Peptide (NH₂-Gly-Gly-Lys-Gly-Arg-Val-Gly-Leu-Pro-Gly-Cys-SH) was fixed on the rGO-Au-PMB/glass carbon electrode. Pt nanoparticle-aminoferrocene-bovine serum albumin (PtNP-amFc-BSA) was chemically linked to the immobilized peptide, behaving a strong current signal at 0.2 V. The increase of current signal at −0.18 V and the decrease of current signal at 0.2 V of the biosensor were obtained by matrix metalloproteinase-2 (MMP-2, a target analyte) cleaving the immobilized PtNP-amFc-BSA-peptide. The current signal differences of rGO-Au-PMB (ΔI_substrate) and PtNP-amFc-BSA (ΔI_probe) before and after incubated with MMP-2 were monitored. The synergistic effect of redox substrate and immunoprobe behaved as a better linear relationship between ΔI (ΔI_substrate + ΔI_probe) and lgC_MMP-2 (ng mL⁻¹), resulting in a significantly improved sensitivity 43.86 μA·(lgC_MMP-2)⁻¹, which was three-fold higher than those of previous works.

提出了一种基于双信号协同效应有效提高安培生物传感器灵敏度的新策略。通过一步法合成了还原的氧化石墨烯-Au-聚（亚甲基蓝）（rGO-Au-PMB），它是在-0.18 V处具有强电流信号的新型氧化还原物质，并用于制造生物传感器的基板。肽（NH ₂（Gly-Gly-Lys-Gly-Arg-Val-Gly-Leu-Pro-Gly-Cys-SH）固定在rGO-Au-PMB /玻璃碳电极上。Pt纳米颗粒-氨基二茂铁-牛血清白蛋白（PtNP-amFc-BSA）与固定的肽化学连接，在0.2 V时具有强电流信号。在-0.18 V时电流信号增加，而在0.2 V时电流信号减少通过裂解固定化的PtNP-amFc-BSA-肽的基质金属蛋白酶-2（MMP-2，一种目标分析物）获得了生物传感器的一部分。监测与MMP-2孵育前后rGO -Au-PMB（ΔI_底物）和PtNP-amFc-BSA（ΔI_探针）的电流信号差。氧化还原底物与免疫_探针的协同作用表现为ΔI（ΔI_底物 +ΔI_探针之间的线性关系更好）和lgC _MMP-2（ng mL ^-1），灵敏度显着提高了43.86μA·（lgC _MMP-2）^-1，比以前的研究提高了三倍。