Surface plasmon resonance biosensor using hydrogel-AuNP supramolecular spheres for determination of prostate cancer-derived exosomes

Based on the hydrogel-AuNP supramolecular sphere (H-Au), a label-free and real-time surface plasmon resonance imaging biosensor has been developed for highly sensitive and specific determination of prostate cancer cell-derived exosomes. After integrating the signal amplification effect of the mass cumulative hydrogel and the LSPR effect of AuNPs with high specific aptamer, the SPRi biosensor for exosome detection exhibited a wide linear range from 1.00 × 10 5 to 1.00 × 10 7 particles/mL with a limit of detection of 1.00 × 10 5 particles/mL. Most importantly, with a strong correlation between the SPRi signal and the t-PSA value measured by the clinical chemiluminescence immunoassay, this biosensor displayed excellent practicability for human serum analysis, which exhibits great potential applications in disease diagnosis and bioanalysis. Graphical abstract Prostate cancer has been one of the most threatening diseases in human life and health nowadays. In particular, as cancer metastasizes, it is more likely to cause fracture, paraplegia, and even fatal consequences. However, the predominant t-PSA test needs further improvement for the deficiencies of limited specificity and sensitivity, which is prone to false positive. As one of the noninvasive markers of liquid biopsies, exosome has the potential to be a substitute for t-PSA, which can provide specific and predictive information in disease diagnosis and prognosis. Herein, based on the hydrogel-AuNP supramolecular sphere (H-Au), a label-free and real-time surface plasmon resonance biosensor has been developed for highly sensitive and specific detection of prostate cancer cell-derived exosomes. After integrating the signal amplification effect of mass cumulative hydrogel and LSPR effect of AuNPs with high specific aptamer, this developed SPRi biosensor for exosome detection exhibited a wide linear range from 1.00 × 10 5 to 1.00 × 10 7 particles/mL with a limit of detection down to 1.00 × 10 5 particles/mL. Most importantly, with a strong correlation between the SPRi signal and the t-PSA value measured by the clinical chemiluminescence immunoassay, this biosensor displayed excellent practicability in human serum, which exhibited great potential applications in disease diagnosis and bioanalysis.