School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Wang Chan Valley, Rayong 21210, Thailand.
Anal Chem. 2022 Mar 29;94(12):4919-4923. doi: 10.1021/acs.analchem.1c05202. Epub 2022 Mar 21.
We report the production and characterization of effective amperometric sensors for cathodic hydrogen peroxide (HO) detection. The proposed electrodes involve a combination of a HO-signaling Prussian Blue (PB)/carbon nanotube (CNT) layer with a glaze of the biopolymers gelatin (top) and zein (beneath) for protection against PB leakage. The sandwich-type sensor was constructed through simple "drop and dry" steps with (1) suspensions of the CNTs in a soluble PB solution, (2) zein in ethanol, and (3) gelatin in water, applied sequentially to the carbon working electrode disk of a screen-printed carbon electrode (SPCE) platform. The PB in the signaling layer acted as the electrocatalyst for HO reduction at -150 mV vs Ag/AgCl/3 M KCl, enabling cathodic HO amperometry with good target proportionality. Calibration trials confirmed the linearity of the response up to 700 μM ( > 0.998), with a sensitivity of 0.425 μA μM cm and a practical detection limit of 1 μM. Quantification of HO in model and real samples with gelatin-zein-PB/CNT-SPCEs had a recovery of close to 100% of the true value. Since they are easily and cheaply made and yield accurate target assessments, gelatin-zein-PB/CNT-SPCEs are an ideal tool for electrochemical HO analyses in human body fluids, health care products, and samples from industries that use HO as a bleach and germicide. Workers with little experience in sensor fabrication and limited funding will particularly benefit from utilization of the proposed HO probes, which as well as being used in HO testing also have a potential application as the transducer unit of oxidase-based biosensors with amperometric HO readout.
我们报告了用于检测阴极过氧化氢（HO）的有效电流式传感器的制作和特性。所提出的电极涉及 HO 信号普鲁士蓝（PB）/碳纳米管（CNT）层与生物聚合物明胶（顶部）和玉米醇溶蛋白（底部）釉的组合，以防止 PB 泄漏。夹心型传感器通过简单的“滴干”步骤构建，使用（1） CNT 在可溶性 PB 溶液中的悬浮液，（2）乙醇中的玉米醇溶蛋白和（3）水中的明胶，依次施加到丝网印刷碳电极（SPCE）平台的碳工作电极盘上。信号层中的 PB 充当 HO 在-150 mV 相对于 Ag/AgCl/3 M KCl 还原的电催化剂，使 HO 阴极电流法具有良好的目标比例性。校准试验证实，响应的线性度高达 700 μM（>0.998），灵敏度为 0.425 μA μM cm，实际检测限为 1 μM。使用明胶-玉米醇溶蛋白-PB/CNT-SPCE 对模型和真实样品中的 HO 进行定量，其回收率接近真实值的 100%。由于它们易于制造且价格低廉，并且能够准确评估目标，因此明胶-玉米醇溶蛋白-PB/CNT-SPCE 是电化学 HO 分析在人体液、保健品和使用 HO 作为漂白剂和杀菌剂的工业样品中的理想工具。在传感器制造方面经验有限且资金有限的工人将特别受益于所提出的 HO 探头的利用，这些探头除了用于 HO 测试外，还有可能作为基于氧化酶的生物传感器的换能器单元，具有电流式 HO 读出功能。
