Garcia Cruz Alvaro, Haq Isma, Cowen Todd, Di Masi Sabrina, Trivedi Samir, Alanazi Kaseb, Piletska Elena, Mujahid Adnan, Piletsky Sergey A
Department of Chemistry, University of Leicester, University Road, LE1 7RH, Leicester, UK.
Institute of Chemistry, University of the Punjab, Quaid-e-Azam Campus, Lahore, Pakistan.
Biosens Bioelectron. 2020 Dec 1;169:112536. doi: 10.1016/j.bios.2020.112536. Epub 2020 Aug 28.
A robust and highly specific sensor based on electroactive molecularly imprinted polymer nanoparticles (nanoMIP) was developed. The nanoMIP tagged with a redox probe, combines both recognition and reporting capabilities. The developed nanoMIP replaces enzyme-mediator pairs used in traditional biosensors thus, offering enhanced molecular recognition for insulin, improving performance in complex biological samples, and yielding high stability. Also, most of existing sensors show poor performance after storage. To improve costs of the logistics and avoid the need of cold storage in the chain supply, we developed an alternative to biorecognition system that relies on nanoMIP. NanoMIP were computationally designed using "in-silico" insulin epitope mapping and synthesized by solid phase polymerisation. The characterisation of the polymer nanoparticles was performed by transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier-transform Infrared (FT-IR) and surface plasmon resonance (SPR). The electrochemical sensor was developed by chemical immobilisation of the nanoMIP on screen printed platinum electrodes. The insulin sensor displayed satisfactory performances and reproducible results (RSD = 4.2%; n = 30) using differential pulse voltammetry (DPV) in the clinically relevant concentration range from 50 to 2000 pM. The developed nanoMIP offers the advantage of large number of specific recognition sites with tailored geometry, as the resultant, the sensor showed high sensitivity and selectivity to insulin with a limit of detection (LOD) of 26 and 81 fM in buffer and human plasma, respectively, confirming the practical application for point of care monitoring. Moreover, the nanoMIP showed adequate storage stability of 168 days, demonstrating the robustness of sensor for several rounds of insulin analysis.
开发了一种基于电活性分子印迹聚合物纳米颗粒（nanoMIP）的强大且高度特异性的传感器。用氧化还原探针标记的nanoMIP兼具识别和报告能力。所开发的nanoMIP取代了传统生物传感器中使用的酶 - 介体对，从而对胰岛素具有增强的分子识别能力，在复杂生物样品中性能得到改善，并具有高稳定性。此外，大多数现有传感器在储存后性能不佳。为了降低物流成本并避免在供应链中进行冷藏的需求，我们开发了一种依赖于nanoMIP的生物识别系统替代方案。使用“计算机模拟”胰岛素表位图谱对nanoMIP进行计算设计，并通过固相聚合合成。通过透射电子显微镜（TEM）、动态光散射（DLS）、傅里叶变换红外光谱（FT - IR）和表面等离子体共振（SPR）对聚合物纳米颗粒进行表征。通过将nanoMIP化学固定在丝网印刷铂电极上开发了电化学传感器。在50至2000 pM的临床相关浓度范围内，使用差分脉冲伏安法（DPV）时，胰岛素传感器表现出令人满意的性能和可重复的结果（相对标准偏差RSD = 4.2%；n = 30）。所开发的nanoMIP具有大量具有定制几何形状的特异性识别位点的优势，因此，该传感器对胰岛素表现出高灵敏度和选择性，在缓冲液和人血浆中的检测限（LOD）分别为26和81 fM，证实了其在即时检测监测中的实际应用。此外，nanoMIP显示出168天的足够储存稳定性，证明了该传感器在多轮胰岛素分析中的稳健性。
