Department of Chemistry, Institute of BioPhysio Sensor Technology (IBST), Pusan National University, Busan 46241, South Korea.
Department of Biomedical Engineering, Dong-A University, College of Medicine, Busan 602-714, South Korea.
Biosens Bioelectron. 2017 May 15;91:128-135. doi: 10.1016/j.bios.2016.12.038. Epub 2016 Dec 15.
A disposable microfluidic amperometric dual-sensor was developed for the detection of glycated hemoglobin (HbA) and total hemoglobin (Hb), separately, in a finger prick blood sample. The accurate level of total Hb was determined through the measurements of the cathodic currents of total Hb catalyzed by a toluidine blue O (TBO)-modified working electrode. Subsequently, after washing unbound Hb in the fluidic channel of dual sensor with PBS, the cathodic current by only HbA captured on aptamer was monitored using another aptamer/TBO-modified working electrode in the channel. To modify the sensor probe, poly(2,2´:5´,5″-terthiophene-3´-p-benzoic acid) and a multi-wall carbon nanotube (MWCNT) composite layer (pTBA@MWCNT) was electropolymerized on a screen printed carbon electrode (SPCE), followed by immobilization of TBO for the total Hb probe and aptamer/TBO for the HbA probe, respectively. The characterization of each sensor surface was performed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS), quartz crystal microbalance (QCM), field-emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The experimental conditions affecting the analytical signal were optimized in terms of the amount of TBO, pH, temperature, binding time, applied potential, and the content ratio of monomer and MWCNT. The dynamic ranges of Hb and HbA were from 0.1 to 10µM and from 0.006 to 0.74µM, with detection limits of 82(±4.2)nM and 3.7(±0.8)nM, respectively. The reliability of the proposed microfluidic dual-sensor for a finger prick blood sample (1µL) was evaluated in parallel with a conventional method (HPLC) for point-of-care analysis.
一种一次性微流控安培双传感器被开发出来,用于分别检测指尖血样中的糖化血红蛋白(HbA)和总血红蛋白(Hb)。通过测量全血中总 Hb 被甲苯胺蓝 O(TBO)修饰的工作电极催化的阴极电流,准确地测定全 Hb 的水平。随后,在双传感器的流体通道中用 PBS 冲洗未结合的 Hb 后,仅在通道中使用另一个与 aptamer 结合的 aptamer/TBO 修饰的工作电极监测仅结合的 HbA 的阴极电流。为了修饰传感器探头,聚(2,2':5',5″-三噻吩-3′-对苯甲酸)和多壁碳纳米管(MWCNT)复合层(pTBA@MWCNT)在丝网印刷碳电极(SPCE)上电聚合,随后分别固定 TBO 作为总 Hb 探针和 aptamer/TBO 作为 HbA 探针。使用循环伏安法(CV)、电化学阻抗谱(EIS)、X 射线光电子能谱(XPS)、石英晶体微天平(QCM)、场发射扫描电子显微镜(FE-SEM)和透射电子显微镜(TEM)对每个传感器表面进行了表征。根据 TBO 的量、pH 值、温度、结合时间、施加电位和单体与 MWCNT 的含量比,优化了影响分析信号的实验条件。Hb 和 HbA 的动态范围分别为 0.1 至 10µM 和 0.006 至 0.74µM,检测限分别为 82(±4.2)nM 和 3.7(±0.8)nM。与传统方法(HPLC)相比,该微流控双传感器对指尖血样(1µL)的可靠性进行了评估,可用于即时分析。