Recent advance in single-molecule detection and imaging

Single-molecule detection and imaging have provided a powerful toolbox for exploring the molecular basis of life. In contrast to conventional ensemble measurements, single-molecule detection technique can directly observe and investigate the properties, behaviors, and interactions of individual molecules at the molecular level. The capability of measuring single biomolecules with good specificity and high accuracy is of great importance in biosensing, bioimaging, biomedical research and diseases diagnosis. Single-molecule detection technique can be used for characterizing and measuring various biomarkers due to its unique advantages of high resolution, ultrahigh sensitivity, visualization capability, and minimal sample consumption. Herein, we review the recent advance in fluorescence-, electrochemiluminescence- and surface-enhanced Raman scattering (SERS)-based single molecule detection and imaging for sensitive measurement of nucleic acids, proteins, viruses, living cells, and exosomes in clinical samples. We summarize the working principles and applications of these technologies, and discuss the current challenges and future perspectives in this field as well.