Nelis Joost L D, Migliorelli Davide, Mühlebach Lea, Generelli Silvia, Stewart Linda, Elliott Christopher T, Campbell Katrina
Institute for Global Food Security, Queen's University, Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, UK.
CSEM SA, Bahnhofstrasse 1, 7302, Landquart, Switzerland.
Talanta. 2021 Jun 1;228:122215. doi: 10.1016/j.talanta.2021.122215. Epub 2021 Feb 16.
A novel electrochemical immunosensor for the detection of the important marine biotoxins domoic acid (DA) and okadaic acid (OA) was developed. The sensors used carbon black modified screen-printed electrodes (CB-SPE) obtained using a high-throughput method. The electrochemical performance and stability of CB modified SPEs and bare carbon SPEs (c-SPEs) were compared using cyclic voltammetry and electrochemical impedance spectroscopy. CB-SPEs showed improved long-term (at least six months) stability and electro-catalytic properties compared with c-SPEs. The CB-SPEs were bio-functionalized with DA or OA protein-conjugates and used to develop two indirect competitive immunosensors using differential pulse voltammetry (DPV). The DPV signals obtained for the OA and DA immunosensors fitted well to four-parameter dose-response curves (R > 0.98) and showed excellent LODs (LOD = 1.7 ng mL for DA in buffer; LOD = 1.9 ng mL for DA in mussel extract; LOD = 0.15 ng mL for OA in buffer; LOD = 0.18 ng mL for OA in mussel extract). No significant interference of the naturally co-occurring marine toxins saxitoxin, tetrodotoxin and OA was detected for the DA immunosensor. Similarly, for the OA immunosensor saxitoxin, tetrodotoxin and DA did not cross-react and very limited interference was observed for the dinophysis toxins DTX-1, DTX-2 and DTX-3 (OA congeners). Moreover, both immunosensors remained stable after at least 25 days of storage at 4 °C. This work demonstrates the potential of affordable, mass-produced nanomaterial-modified SPEs for marine toxin detection in shellfish.
开发了一种用于检测重要海洋生物毒素软骨藻酸（DA）和冈田酸（OA）的新型电化学免疫传感器。该传感器使用通过高通量方法获得的炭黑修饰丝网印刷电极（CB-SPE）。使用循环伏安法和电化学阻抗谱比较了CB修饰的SPE和裸碳SPE（c-SPE）的电化学性能和稳定性。与c-SPE相比，CB-SPE显示出改善的长期（至少六个月）稳定性和电催化性能。CB-SPE用DA或OA蛋白缀合物进行生物功能化，并用于使用差分脉冲伏安法（DPV）开发两种间接竞争免疫传感器。OA和DA免疫传感器获得的DPV信号与四参数剂量响应曲线拟合良好（R>0.98），并显示出优异的检测限（缓冲液中DA的检测限=1.7 ng/mL；贻贝提取物中DA的检测限=1.9 ng/mL；缓冲液中OA的检测限=0.15 ng/mL；贻贝提取物中OA的检测限=0.18 ng/mL）。对于DA免疫传感器，未检测到天然共存的海洋毒素石房蛤毒素、河豚毒素和OA的显著干扰。同样，对于OA免疫传感器，石房蛤毒素、河豚毒素和DA没有交叉反应，并且对鳍藻毒素DTX-1、DTX-2和DTX-3（OA同系物）观察到非常有限的干扰。此外，两种免疫传感器在4°C下储存至少25天后仍保持稳定。这项工作证明了价格合理、可大规模生产的纳米材料修饰SPE在贝类海洋毒素检测中的潜力。
