Wang Shuai, Zhao Aili, Li Guohui, Sun Xiaofeng, Wang Jingui, Cui Min
School of Chemistry and Chemical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, P.R. China.
Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), College of Chemistry, Nankai University, Tianjin 300071, P.R. China.
Anal Chem. 2024 Dec 24;96(51):20287-20295. doi: 10.1021/acs.analchem.4c05144. Epub 2024 Dec 11.
The significant challenge in achieving regeneration for conventional molecularly imprinted polymers (MIPs) restricts their promising application in continuous monitoring of biochemical molecules closely related to human health, especially nonelectroactive molecules. This is because they are either limited to a single use or require removal of imprinted templates through chemical washing steps, which is clearly impractical for sustainable monitoring. Here, a class of regenerable MIP biosensors, taking nonelectroactive branched-chain amino acids (BCAAs) as templates and methyldopa as a functional monomer, was engineered to achieve repeatable regeneration and target recognition. The regeneration was realized through an amperometric - technique with a negative voltage (-0.9 V) according to intrinsic isoelectric points of analytes instead of conventional wash steps. This electrochemical extraction process not only maximally repelled the imprinted templates, creating a large number of cavities (recognition sites) and significantly enhancing sensitivity, but also ensured the successful regeneration of developed biosensing interfaces. The template extraction was evaluated by examining changes in the surface morphology, elemental composition, distribution, content, and interfacial properties. The developed BCAA MIP biosensors achieved sensitive target detection with the linear range from 0.001 to 10.0 μg/mL and limits of detection down to 0.45 (Leu), 0.47 (Ile), and 0.31 (Val) ng/mL. Beyond that, the biosensors demonstrated an excellent ability in decreasing biofouling, realizing repeatable target detection in human sweat, and the obtained results were highly consistent with those of the enzyme-linked immunosorbent assay, indicating high feasibility, reliability, and accuracy in practical application. Meanwhile, the biosensors showed excellent specificity, selectivity, and stability.
传统分子印迹聚合物（MIP）实现再生面临的重大挑战限制了其在与人类健康密切相关的生化分子（尤其是非电活性分子）连续监测中的应用前景。这是因为它们要么仅限于一次性使用，要么需要通过化学洗涤步骤去除印迹模板，这对于可持续监测显然是不切实际的。在此，设计了一类以非电活性支链氨基酸（BCAA）为模板、甲基多巴为功能单体的可再生MIP生物传感器，以实现可重复的再生和目标识别。根据分析物的固有等电点，通过施加负电压（-0.9 V）的安培技术实现再生，而不是传统的洗涤步骤。这种电化学提取过程不仅最大限度地排斥了印迹模板，产生了大量的空穴（识别位点）并显著提高了灵敏度，还确保了所开发的生物传感界面的成功再生。通过检查表面形态、元素组成、分布、含量和界面性质的变化来评估模板提取。所开发的BCAA MIP生物传感器实现了灵敏的目标检测，线性范围为0.001至10.0μg/mL，检测限低至0.45（亮氨酸）、0.47（异亮氨酸）和0.31（缬氨酸）ng/mL。除此之外，该生物传感器在减少生物污垢方面表现出色，能够在人汗液中实现可重复的目标检测，并且所获得的结果与酶联免疫吸附测定的结果高度一致，表明其在实际应用中具有很高的可行性、可靠性和准确性。同时，该生物传感器还表现出优异的特异性、选择性和稳定性。
