Soomro Razium A, Kumar Jai, Neiber Rana R, Alotaibi Amerah M, Shaikh Shoyebmohamad F, Ahmed Nazeer, Nafady Ayman
State Key Laboratory of Organic-Inorganic Composites, Beijing Key Laboratory of Electrochemical Process and Technology for Materials, Beijing University of Chemical Technology, Beijing, 100029, China.
College of Chemical Engineering, University of Chinese Academy of Sciences, 19 A Yuquan Road, Beijing, 100049, China.
Anal Chim Acta. 2023 Apr 22;1251:341016. doi: 10.1016/j.aca.2023.341016. Epub 2023 Feb 27.
The rapid-charge carrier recombination and low conductivity are critical in devising an efficient photoelectrochemical (PEC) sensor. Herein, we propose partial oxidation of few-layered MXene (TiCT) to construct a photo-active TiO/TiCT platform that could be configured for PEC sensing of folate receptors (FR), particularly, FR-expressing breast cancer cells (MDA-MB-231). MXene-TiCT dispersion was oxidized in natural-open air conditions, where continuous exposure for six (06) days allowed for homogeneous in-situ growth of TiO over MXenes nanosheets (MX-06). This exposure enabled partial oxidation of MXene-sheets with a balanced TiO to MXene content that could exhibit improved photoresponsive characteristics owing to the synergism of redox-active TiO and highly conductive underlying TiCT. The photoelectrode was then adapted for biorecognition by conjugating chitosan and folic acid (FA) networks, which permitted selective detection of FR-expressed cells with significant antifouling capabilities against common proteins such as bovine serum album (BSA), hemoglobin, and immunoglobulin G. (Ig G). The detection mechanism relies on FA's strong affinity for cancer cell folate receptors, which proportionally inhibited the photoelectrodes PEC oxidation response to ascorbic acid (AA)(mediator). The proposed inhibition strategy enabled sensitive detection of FR-expressed MDA-MB-231 cells in the concentration range of 1 × 10 to 2 × 10 cells/mL with a detection limit of 1.01 cells/mL (S/N = 3).
快速电荷载流子复合和低电导率是设计高效光电化学（PEC）传感器的关键因素。在此，我们提出对少层MXene（TiCT）进行部分氧化，以构建一个光活性TiO/TiCT平台，该平台可用于叶酸受体（FR）的PEC传感，特别是用于检测表达FR的乳腺癌细胞（MDA-MB-231）。MXene-TiCT分散体在自然开放空气条件下被氧化，连续暴露六（06）天可使TiO在MXene纳米片（MX-06）上均匀原位生长。这种暴露使MXene片部分氧化，TiO与MXene的含量达到平衡，由于氧化还原活性TiO与高导电性的底层TiCT的协同作用，该平台可表现出改善的光响应特性。然后，通过结合壳聚糖和叶酸（FA）网络，使光电极适用于生物识别，从而能够选择性检测表达FR的细胞，对牛血清白蛋白（BSA）、血红蛋白和免疫球蛋白G（Ig G）等常见蛋白质具有显著的抗污能力。检测机制依赖于FA对癌细胞叶酸受体的强亲和力，这会按比例抑制光电极对抗坏血酸（AA）（介质）的PEC氧化响应。所提出的抑制策略能够在1×10至2×10个细胞/mL的浓度范围内灵敏检测表达FR的MDA-MB-231细胞，检测限为1.01个细胞/mL（S/N = 3）。
