Photo-induced multiple charge transfer resonance of Ce-MOF for SERS detection of nucleic acid

Abstract

Background

Sensitive and accurate detection of important cancer markers MicroRNAs (miRNAs) is critical to prevent and treat disease. Among many detection techniques, surface-enhanced Raman scattering(SERS) has attracted much attention due to its advantages such as narrow spectral peak, low interference and non-destructive detection. Interestingly, non-noble metal SERS substrates show good prospects due to their outstanding spectral reproducibility and biocompatibility. However, the low SERS sensitivity of non-noble metal substrates also limited their detection performance. Therefore, it is crucial to design a non-noble metal substrate with high SERS sensitivity for nucleic acid detection.

Results

In this study, we found that the photo induction (30 min) of Ce-MOF has high SERS performance (abbreviated as Ce-MOF₃₀). It is due to that photo-induction can regulate the energy level of the Ce-MOF and break the benzene-C bonds to introduce a defect energy level, which provides additional charge transfer channels. The Ce-MOF₃₀ substrates can achieve an enhancement factor (EF) of 6.71 × 10⁶ for Methylene blue (MB), about 7-fold higher than pristine Ce-MOF, which is the best Ce-based SERS substrate so far. Finally, a SERS detection platform was fabricated by combining the Mg²⁺ assisted dual signal amplification for miRNA 141 assay, and the detection limit was 1.72 fM.

Significance

This work proposed a simple photo-induction strategy to enhance SERS performance, which supplied a new detection platform for detection of nucleic acid and further expand the application of non-noble metal substrate in SERS field.