Intelligent Convergence Research Laboratory, Electronics and Telecommunications Research Institute, 34129, Daejeon, Republic of Korea.
Graduate School of Analytical Science and Technology, Chungnam National University, 34134, Daejeon, Republic of Korea.
Sci Rep. 2022 May 25;12(1):8815. doi: 10.1038/s41598-022-12444-6.
A novel and facile post-mortem interval (PMI) biosensor was fabricated using a double-label strategy to detect the glyceraldehyde 3-phosphate dehydrogenase (GAPDH) biomarker. A monoclonal anti-GAPDH antibody was immobilized on a surface label containing cadmium selenide quantum dots (CdSe QDs) on a cysteamine graphene oxide (Cys-GO) self-assembled monolayer. Glucose oxidase (GOx) was used as a signal label to conjugate with GAPDH. GAPDH recognition was achieved through the dissolution of the surface-attached CdSe QDs by hydrogen peroxide generated through GAPDH-conjugated GOx-catalyzed β-glucose oxidation. To enhance sensitivity, a competitive interaction was introduced between free and conjugated GAPDH to the active site of the anti-GAPDH antibody. The electrochemical response due to CdSe dissolution decreased proportionally with the concentration of free GAPDH. Differential pulsed voltammetry was conducted to determine the analytical characteristics of the immunosensor, including the limit of detection, linear dynamic range, target selectivity, system stability, and applicability toward the analysis of real samples.
一种新型的简便死后间隔（PMI）生物传感器是使用双标记策略制造的，用于检测甘油醛 3-磷酸脱氢酶（GAPDH）生物标志物。单克隆抗 GAPDH 抗体固定在含有硒化镉量子点（CdSe QDs）的表面标记物上，该标记物位于半胱氨酸石墨烯氧化物（Cys-GO）自组装单层上。葡萄糖氧化酶（GOx）用作信号标记物，与 GAPDH 结合。GAPDH 的识别是通过 GAPDH 结合的 GOx 催化的β-葡萄糖氧化产生的过氧化氢溶解表面附着的 CdSe QDs 来实现的。为了提高灵敏度，在游离和共轭 GAPDH 与抗 GAPDH 抗体的活性位点之间引入了竞争相互作用。由于 CdSe 溶解而引起的电化学响应与游离 GAPDH 的浓度成比例降低。进行差分脉冲伏安法以确定免疫传感器的分析特性，包括检测限、线性动态范围、目标选择性、系统稳定性和对实际样品分析的适用性。
