Chung Saeromi, Sicklick Jason K, Ray Partha, Hall Drew A
Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, California 92093, United States.
Department of Surgery, Division of Surgical Oncology, Moores Cancer Center, University of California San Diego Health, San Diego, California 92093, United States.
ACS Sens. 2021 May 28;6(5):1971-1979. doi: 10.1021/acssensors.1c00535. Epub 2021 May 19.
An electrochemical sensor based on a conformation-changing aptamer is reported to detect soluble KIT, a cancer biomarker, in human serum. The sensor was fabricated with a ferrocene-labeled aptamer ( < 5 nM) conjugated to a gold electrode. Quantitative KIT detection was achieved using electrochemical impedance spectroscopy (EIS) and square-wave voltammetry (SWV). EIS was used to optimize experimental parameters such as the aptamer-to-spacer ratio, aptamer immobilization time, pH, and KIT incubation time, and the sensor surface was characterized using voltammetry. The assay specificity was demonstrated using interfering species and exhibited high specificity toward the target protein. The aptasensor showed a wide dynamic range, 10 pg/mL-100 ng/mL in buffer, with a 1.15 pg/mL limit of detection. The sensor also has a linear response to KIT spiked in human serum and successfully detected KIT in cancer-cell-conditioned media. The proposed aptasensor has applications as a continuous or intermittent approach for cancer therapy monitoring and diagnostics (theranostics).
据报道，一种基于构象变化适配体的电化学传感器可用于检测人血清中的可溶性KIT（一种癌症生物标志物）。该传感器由与金电极共轭的二茂铁标记适配体（<5 nM）制成。使用电化学阻抗谱（EIS）和方波伏安法（SWV）实现了对KIT的定量检测。EIS用于优化实验参数，如适配体与间隔物的比例、适配体固定时间、pH值和KIT孵育时间，并使用伏安法对传感器表面进行表征。通过使用干扰物质证明了该检测方法的特异性，并且对目标蛋白表现出高特异性。该适配体传感器在缓冲液中显示出较宽的动态范围，为10 pg/mL至100 ng/mL，检测限为1.15 pg/mL。该传感器对添加到人类血清中的KIT也具有线性响应，并成功检测到癌细胞条件培养基中的KIT。所提出的适配体传感器可作为一种连续或间歇性方法用于癌症治疗监测和诊断（诊疗一体化）。
