DNA precisely regulated Au nanorods/Ag2S quantum dots satellite structure for ultrasensitive detection of prostate cancer biomarker

Currently, metal-enhanced fluorescence (MEF) is an emerging effective technology for sensitive bio-detection. In this report, the distance between Au nanorods (Au NRs) and NIR Ag2S quantum dots (Ag2S QDs) is precisely regulated by DNA with different chain lengths. The experimental results show that the best MEF effect can be obtained when the distance is about 8 nm. Based on the result, Au NRs and Ag2S QDs were modified with DNA at specific distances, which were used for accurate detection of prostate cancer marker PCA3 with high sensitivity and selectivity. And the designed biosensor show a good linear relationship in the 5-500 pM and a low detection limit of 1.42 pM (S/N = 3) for PCA3. Importantly, the designed metal-enhanced NIR fluorescence satellite structure probe have been successfully applied for sensing PCA3 in human serum samples and lysates of prostate cancer cells (1, 5 and 10 cells), which has significant potential in the field of biosensing, biological analysis and clinical diagnosis.

Automated summary

By precisely regulating the distance between Au nanorods and Ag2S quantum dots with DNA of different chain lengths, the best MEF effect was obtained. Utilizing this, a biosensor for accurate detection of PCA3 was designed with good performance in terms of detection limit and sensitivity.