高灵敏ECL-RET传感器的构建及其用于血清前列腺特异性抗原检测的研究

Construction of a Sensitive Electrochemiluminescence Resonance Energy Transfer Biosensor and Its Application in Detection of Prostate Specific Antigen in Serum

肿瘤标志物在癌症早期诊断与预后监测中具有非常重要意义。前列腺癌作为男性泌尿生殖系统中最常见的恶性肿瘤,其血清前列腺特异性抗原(PSA)是最重要的早期检测指标。该研究以制备的四元Cu-Zn-In-S纳米晶(NCs)作为发光体,金纳米星(AuNSs)作为猝灭探针,利用K2S2O8作为共反应剂,发展了一种基于量子点电化学发光共振能量转移的免疫传感器(ECL-RET)用于血清中PSA的高灵敏检测。固定在传感器上的NCs表现出极强的初始ECL信号和较低的ECL电位。作为固定基底的多壁碳纳米管(MWNTs)不仅加速了NCs与S_(2)O^(2-)_(8)之间的反应,获得了较高的ECL信号,而且作为载体可以固定大量的抗体,提高传感器检测PSA的灵敏度。采用电化学交流阻抗法(EIS)对组装过程进行跟踪,证实了该传感器组装的可行性。采用电化学发光法研究了传感器对底液中不同浓度PSA的响应,结果显示,随着体系中PSA浓度的增加,电极上结合AuNSs的标记抗体(Ab2-AuNSs)越多,触发的猝灭效果越明显,ECL信号降低越明显。因此,该传感器表现出对PSA较好的分析性能,其线性范围为0.01~150 ng/mL,检出限为0.03 ng/mL。用于血清样品的检测,该传感器的测试结果与常用的化学发光法基本吻合,相对误差仅为−7.2%~6.0%,结果准确度良好,为临床检测PSA提供了准确可靠的新方法。

The accurate and rapid quantitative detection on cancer biomarkers is of great significance to early diagnosis and prognosis monitoring,especially for prostate cancer,the most common malignant tumor in male genitourinary system,its prostate specific antigen(PSA)is the most important early detection index for blood serum.Herein,an electrochemiluminescence resonance energy transfer immunosensor(ECL-RET)was constructed for the ultrasensitive detection of PSA in serum,with quaternary Cu-Zn-In-S nanocrystals(NCs)as the ECL donor and gold nanostars(AuNSs)as the acceptor.The immunosensor exhibited a very strong initial ECL signal and a low ECL potential.The multi-walled carbon nanotubes(MWNTs)attached on the substrate not only accelerated the reaction between NCs and S_(2)O^(2-)_(8) to obtain a high ECL signal,but also assembled a large number of antibodies to improve the sensitivity of the sensor as a carrier.The electrochemical impedance spectroscopy(EIS)was used to investigate the assembly process,and electrochemiluminescence(ECL)was used to study the response to different concentrations of PSA.The proposed ECL-RET immunosensor possessed a good analytical performance,with a wide linear range of 0.01-150 ng/mL and a detection limit(S/N=3)of 0.03 ng/mL.In addition,the ECL-RET immunosensor was successfully applied to the determination of PSA in human serum samples,with relative errors of-7.2%-6.0%,indicating that the proposed immunosensor is a promising tool for PSA detection in real samples.