Nanoparticle-based electrochemiluminescence cytosensors for single cell level detection

Abstract Electrochemiluminescence (ECL) sensing have been widely studied for analytical sensing and biological analysis with high sensitivity, simplified optical setup, wide detection range, and low background noise. Recently, a few researches about nanoparticle (NP)-based ECL cytosensor and cell ECL imaging have been reported, which provide a significant boost for single cell detection, early cancer diagnosis, clinical analysis and therapeutic monitoring. The unique optical and electrical function of the NPs have benefited the ECL biosensing strategies for analysis of the intra- and extracellular molecules of a single cell. Therefore, this review presents the last advances and developments related to novel NP-based ECL biosensor for cell analysis and imaging using. After a brief overview of basic ECL principles, a discussion of the different work roles of NPs in ECL cellular sensing is presented, including carbon-based nanomaterials, quantum dots, noble metal NPs, nanoclusters, and so on. These NPs worked not only as ECL luminophores and coreaction catalysts, but also as ECL luminophores encapsulates, carriers and electrode modification materials. The NP-based ECL cytosensor is showing more promising potentials in ultrasensitive and real-time cellular analysis. We also emphasize the critical sensing methodology and construction strategies NP-based ECL cytosensors. The advantages and limitations are also considered in focusing on the NP-based ECL cytosensing and imaging systems. Then the current representative research of NP-based ECL cytosensors with single cell level detection are highlighted, such as cell recognition and tracking, in-situ evaluation of potential biomarkers, dynamic monitoring of cell-surface carbohydrate expression, nucleic acid detection, intracellular small molecules sensing, and single cell imaging. Finally, future outlooks and challenges are featured on the view of bioanalysis and clinical diagnostics.