State Key Laboratory of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023 China.
State Key Laboratory of Analytical Chemistry for Life Science and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023 China.
Biosens Bioelectron. 2016 Dec 15;86:683-689. doi: 10.1016/j.bios.2016.07.067. Epub 2016 Jul 20.
Herein, a spatial-resolved electrochemiluminescene (ECL) ratiometry based on a closed biopolar electrode (BPE) is reported for the highly sensitive detection of prostate specific antigen (PSA). Au@g-C3N4 NCs as one ECL emitter were firstly coated on the cathode of BPE, while the anode of the BPE served for calibration via another ECL substance, Ru(bpy)3(2+). The electroneutrality across the BPE makes the reactions on each pole of BPE electrically coupled. Thus one electrochemical sensing reaction at one pole of BPE could be quantified at both ends. A composite, Pt-PAMAM-DNAzyme was assembled on the surface of cathode via DNA hybridization between probe DNA and PSA aptamer. It acted as an ECL quencher of g-C3N4 via resonance energy transfer (RET) and catalyzing the reduction of O2, the co-reactant of g-C3N4. Meanwhile, it could promote the ECL of Ru(bpy)3(2+) at anode, since the catalytic reduction of O2 at the cathode increased the faradiac current flowing through the BPE. Based on this signal composite, an ECL "off-on" phenomenon was observed at the cathode, after Pt-PAMAM-DNAzyme was "peeled off" by PSA. Conversely, at the anode, an "on-off" ECL changing was obtained. Therefore, a sensitive ratiometry for PSA detection was achieved with a linear range from 0.10 to 200ng/mL. Since the two ECL emitters were physically separated, the ratiometric system was relatively simple and neither optical filters nor spectrometer were required. The strategy combining the ECL ratiometry and BPE broadens the applications of BPE-ECL and shows good perspective in clinical application.
在此，报道了一种基于闭端双极电极（BPE）的空间分辨电化学发光（ECL）比率法，用于高灵敏度检测前列腺特异性抗原（PSA）。首先，将 Au@g-C3N4 NCs 作为一种 ECL 发射器涂覆在 BPE 的阴极上，而 BPE 的阳极则通过另一种 ECL 物质 Ru(bpy)3(2+) 进行校准。BPE 两端的电中性使得 BPE 两极上的反应在电学上相互耦合。因此，BPE 一极上的一个电化学传感反应可以在两端进行定量。通过探针 DNA 与 PSA 适体之间的 DNA 杂交，将 Pt-PAMAM-DNAzyme 组装在阴极表面上。它通过共振能量转移（RET）作为 g-C3N4 的 ECL 猝灭剂，并催化 O2 的还原，O2 是 g-C3N4 的共反应物。同时，它可以促进阳极处 Ru(bpy)3(2+) 的 ECL，因为阴极处 O2 的催化还原增加了流经 BPE 的法拉第电流。基于这种信号复合，当 Pt-PAMAM-DNAzyme 被 PSA“剥离”时，在阴极观察到 ECL“关闭-开启”现象。相反，在阳极，获得了 ECL“开启-关闭”的变化。因此，实现了一种用于 PSA 检测的灵敏比率法，线性范围为 0.10 至 200ng/mL。由于两个 ECL 发射器在物理上是分开的，因此比率系统相对简单，不需要光学滤波器或光谱仪。将 ECL 比率法与 BPE 相结合的策略拓宽了 BPE-ECL 的应用，并在临床应用中显示出良好的前景。
