Surface-Enhanced Electrochemiluminescence Imaging for Multiplexed Immunoassays of Cancer Markers in Exhaled Breath Condensates

Abstract

Recently we have demonstrated that the surface plasmon of noble metal nanoparticles can effectively enhance the ECL intensity of Ru­(bpy)3 2+, and we named this detection principle as surface-enhanced electrochemiluminescence (SEECL-I). However, SEECL based on photomultiplier tube (PMT) detection can only detect one target at a time, which is not suitable for multiple targets detection. In this work, we combined our previous developed SEECL with a bioimaging device to develop a novel multiplexed immunassay for simultaneous and fast analysis of cancer markers. A core–shell nanocomposite consisted of gold–silicon dioxide nanoparticles doped with Ru­(bpy)3 2+(Au@SiO2-Ru) with strong ECL emission was employed as ECL label due to the localized surface plasmon resonance (LSPR) of AuNPs, which can significantly enhance the ECL emission of Ru­(bpy)3 2+. The ECL signals from the 4 × 4 electrode arrays were collected using the constant potential method (current–time curve method) imaging with a sCOMS camera. As a proof-of-concept application, we demonstrated the use of the proposed SEECL-I for simultaneous detection of carcinoembryonic antigen (CEA), neuron specific enolase (NSE), and squamous cell carcinoma antigen (SCC) in exhaled breath condensates (EBCs) with low detection limit (LOD) of 0.17, 0.33, and 0.33 pg/mL (S/N = 3), respectively. The results demonstrated that the proposed SEECL-I strategy can provide a high sensitivity, fast analysis, and high-throughput platform for clinical diagnosis of cancer markers in EBCs.

Framework and Spherical Nucleic Acids Synergistically Enhanced Electrochemiluminescence Nanosensors for Rapidly Diagnosing Acute Myocardial Infarction Based on Circulating MicroRNA Levels

“…However, these AMI-related miRNAs exist in patients’ circulating blood at extremely low levels, and nucleic acid amplification strategies are usually required to improve the detection sensitivity of them at the cost of time. − Accordingly, balancing the needs of rapid analysis and ultrahigh sensitivity is still a hurdle for the clinical detection of AMI-related miRNAs. Meanwhile, considering the good sensitivity and specificity of electrochemiluminescence (ECL), , here we seek to develop a direct ECL nanosensor synergistically enhanced by framework and spherical nucleic acids, which circumvents the time-consuming signal amplification procedures.…”

Coreactant-free and Near-Infrared Electrochemiluminescence Immunoassay with n-Type Au Nanocrystals as Luminophores

“…A linear relationship between the maximum coreactant-free ECL intensity and the logarithm of CEA concentration is obtained from 0.1 to 50 pg/mL ( R 2 = 0.993, inset of Figure A) with a limit of detection (LOD) of 0.03 pg/mL (S/N = 3). The LOD of coreactant-free ECL immunoassay is superior to that of CL immunoassay using the same Met@Au NCs as tags and other recently reported coreactant ECL biosensors. − …”

Strategies for Enhancing the Sensitivity of Electrochemiluminescence Biosensors

“…Previous reports have demonstrated that the localized surface plasmon resonance (LSPR) of metal nanoparticles (such as gold and silver) can significantly enhance the spectral signal [ 89 , 90 ]. LSPR is a physical phenomenon that is generated when the surface plasma of noble metal nanoparticles is irradiated by incident light with the same frequency [ 91 ]. LSPR can generate a local electromagnetic field around noble metal nanoparticles, thus enhancing the spectral signal [ 92 ].…”