Abstract：
To minimize background interference in electrochemical enzymatic biosensors employing electron mediators, it is essential for the electrochemical oxidation of electroactive interfering species (ISs), such as ascorbic acid (AA), to proceed slowly, and for the redox reactions between electron mediators and ISs to occur at a low rate. In this study, we introduce a novel combination of a working electrode and an electron mediator that effectively mitigates interference effects. Compared to commonly used electrodes such as Au, glassy carbon, and indium tin oxide (ITO), boron-doped diamond (BDD) electrodes demonstrate significantly lower anodic current (i.e., lower background levels) in the presence of AA. Additionally, menadione (MD) exhibits notably slower reactivity with AA compared to other electron mediators such as Ru(NH3)63+, 4-amino-1-naphthol, and 1,4-naphthoquinone, primarily due to the lower formal potential of MD compared to AA. This synergistic combination of BDD electrode and MD is effectively applied in three biosensors: (i) glucose detection using electrochemical-enzymatic (EN) redox cycling, (ii) glucose detection using electrochemical-enzymatic-enzymatic (ENN) redox cycling, and (iii) lactate detection using ENN redox cycling. Our developed approach significantly outperforms the combination of ITO electrode and MD in minimizing IS interference. Glucose in artificial serum can be detected with detection limits of ~ 20 μM and ~ 3 μM in EN and ENN redox cycling, respectively. Furthermore, lactate in human serum can be detected with a detection limit of ~ 30 μM. This study demonstrates sensitive glucose and lactate detection with minimal interference, eliminating the need for (bio)chemical agents to remove interfering species.
摘要：
为了最大程度地减少使用电子介体的电化学酶生物传感器中的背景干扰，它对于电活性干扰物质（ISs）的电化学氧化至关重要，如抗坏血酸（AA），慢慢进行，以及电子介体和ISs之间的氧化还原反应以低速率发生。在这项研究中,我们介绍了一种新的工作电极和电子介体的组合，有效地减轻干扰效应。与常用的电极如Au相比，玻璃碳，和氧化铟锡（ITO），掺硼金刚石(BDD)电极显示出显著较低的阳极电流(即，较低的背景水平)在AA的存在下。此外,甲萘醌（MD）与其他电子介体（如Ru（NH3）63+）相比，与AA的反应性明显更慢，4-氨基-1-萘酚,和1,4-萘醌,主要是由于MD的形式潜力低于AA。BDD电极和MD的这种协同组合有效地应用于三种生物传感器：（i）使用电化学-酶（EN）氧化还原循环的葡萄糖检测，（ii）使用电化学-酶-酶（ENN）氧化还原循环进行葡萄糖检测，和(iii)使用ENN氧化还原循环的乳酸检测。我们开发的方法在最小化IS干扰方面明显优于ITO电极和MD的组合。在EN和ENN氧化还原循环中，可以检测到人工血清中的葡萄糖，检出限为〜20μM和〜3μM，分别。此外，可以检测到人血清中的乳酸，检出限为〜30μM。这项研究证明了灵敏的葡萄糖和乳酸检测，干扰最小，消除了对（生物）化学试剂的需要，以消除干扰物种。
