Department of Biological Sciences, Birla Institute of Technology & Science Pilani, Pilani, Rajasthan, 333031, India.
Chembiochem. 2023 Dec 14;24(24):e202300585. doi: 10.1002/cbic.202300585. Epub 2023 Oct 19.
Heavy metal arsenic is a water pollutant that affects millions of lives worldwide. A novel aptamer candidate for specific and sensitive arsenic detection was identified using Graphene Oxide-SELEX (GO-SELEX). Eleven rounds of GO-SELEX were performed to screen As(III) specific sequences. The selected aptamer sequences were evaluated for their binding affinity. The dissociation constant of the best aptamer candidate, As-06 was estimated by fluorescence recovery upon target addition, and it was found to be 8.15 nM. A QCM-based biosensing platform was designed based on the target-triggered release of aptamer from the QCM electrode. An rGO-SWCNT nanocomposite was adsorbed on the gold surface, and the single-stranded probe was stacked on the rGO-CNT layer. Upon addition of the target to the solution, a concentration-dependent release of the ssDNA probe was observed and recorded as the change in the electrode frequency. The developed QCM sensor showed a dynamic linear range from 10 nM to 100 nM and a low detection limit of 8.6 nM. The sensor exhibited excellent selectivity when challenged with common interfering anions and cations.
重金属砷是一种水污染物质，影响着全球数百万人的生活。本研究使用氧化石墨烯-SELEX（GO-SELEX）技术，鉴定出一种新型的、针对砷的高特异性和高灵敏度适配体。经过 11 轮筛选，得到了针对 As(III)的特异性序列。对筛选出的适配体序列进行了结合亲和力评估。通过目标物加入后荧光恢复的方法，计算出最佳适配体候选物 As-06 的解离常数，其值为 8.15 nM。基于适配体在目标物触发下从 QCM 电极上释放的原理，设计了基于 QCM 的生物传感平台。将 rGO-SWCNT 纳米复合材料吸附在金表面，将单链探针堆积在 rGO-CNT 层上。当向溶液中加入目标物时，观察到 ssDNA 探针的浓度依赖性释放，并记录为电极频率的变化。所开发的 QCM 传感器在 10 nM 至 100 nM 的动态线性范围内表现出良好的线性关系，检测限低至 8.6 nM。该传感器在受到常见干扰阴离子和阳离子的挑战时表现出优异的选择性。
