Institute for Global Food Security, School of Biological Sciences, Queen's University, 19 Chlorine Gardens, Belfast, BT9 5DL, UK.
CSEM SA, Bahnhofstrasse 1, 7302, Landquart, Switzerland.
Mikrochim Acta. 2020 Feb 12;187(3):164. doi: 10.1007/s00604-020-4150-x.
Gold nanostars (GNST), gold nanospheres (GNP) and carbon black (CB) are chosen as alternative nanomaterials to modify carbon screen-printed electrodes (c-SPEs). The resulting three kinds of modified c-SPEs (GNP-SPE, CB-SPE and GNSP-SPE) were electrochemically and microscopically characterized and compared with standardized c-SPEs after pretreatment with phosphate buffer by pre-anodization (pre-SPE). The results show outstanding electrochemical performance of the carbon black-modified SPEs which show low transient current, low capacitance and good porosity. A competitive chronoamperometric immunoassay for the shellfish toxin domoic acid (DA) is described. The performances of the CB-SPE, GNP-SPE and pre-SPE were compared. Hapten-functionalized magnetic beads were used to avoid individual c-SPE functionalization with antibody while enhancing the signal by creating optimum surface proximity for electron transfer reactions. This comparison shows that the CB-SPE biosensor operated best at a potential near - 50 mV (vs. Ag/AgCl) and enables DA to be determined with a detection limit that is tenfold lower compared to pre-SPE (4 vs. 0.4 ng mL). These results show very good agreement with HPLC data when analysing contaminated scallops, and the LOD is 0.7 mg DA kg of shellfish. Graphical abstractSchematic representation of the magnetic bead-based immunoassay for the quantification of domoic acid (DA) in shellfish with nanomaterial-modified screen-printed electrodes. CB, carbon black; GNP, gold nanospheres; GNST, gold nanostars; MB, magnetic beads; DA-mAb, anti-DA monoclonal mouse antibody; HRP-pAb, horseradish conjugated polyclonal goat anti-mouse antibody; DA-BSA, bovine serum albumin conjugated DA; HQ, hydroquinone; BQ, benzoquinone.
金纳米星（GNST）、金纳米球（GNP）和炭黑（CB）被选为修饰碳丝网印刷电极（c-SPE）的替代纳米材料。通过预阳极氧化（预-SPE）用磷酸盐缓冲液预处理后，对得到的三种修饰的 c-SPE（GNP-SPE、CB-SPE 和 GNSP-SPE）进行了电化学和显微镜表征，并与标准化的 c-SPE 进行了比较。结果表明，炭黑修饰的 SPE 具有出色的电化学性能，表现出低瞬态电流、低电容和好的多孔性。本文描述了一种用于贝类毒素软骨藻酸（DA）的竞争计时安培免疫分析。比较了 CB-SPE、GNP-SPE 和预-SPE 的性能。半抗原功能化的磁性珠用于避免抗体对单个 c-SPE 的功能化，同时通过为电子转移反应创造最佳的表面接近度来增强信号。这种比较表明，CB-SPE 生物传感器在接近 -50 mV（相对于 Ag/AgCl）的电位下运行最佳，并使 DA 的检测限比预-SPE 低十倍（4 与 0.4 ng mL）。这些结果与分析受污染扇贝时的 HPLC 数据非常吻合，LOD 为 0.7 mg DA kg 贝类。示意图基于纳米材料修饰的丝网印刷电极的贝类毒素软骨藻酸（DA）定量磁性珠免疫测定示意图。CB，炭黑；GNP，金纳米球；GNST，金纳米星；MB，磁性珠；DA-mAb，抗 DA 单克隆鼠抗体；HRP-pAb，辣根过氧化物酶偶联的多克隆山羊抗鼠抗体；DA-BSA，牛血清白蛋白偶联的 DA；HQ，对苯二酚；BQ，苯醌。
