Semiconductor Superstructures with Multiple Synergistic Resonances for SERS Exploring Multiplex Noncovalent Interactions
Jiaojiao Zhao, Lei Sun, Yumiao Dong, Yixuan Chang, Haisu Wang, Zonghao Liu, Junbo Li, Yunfei Xie, Wei Ji
Abstract
Noncovalent interactions (NCIs) are crucial for biological bond-forming events and have significant applications across various branches of chemistry. Here, we demonstrate for the first time the identification of multiple NCIs between two interacting species using semiconductor-based surface-enhanced Raman scattering (SERS) spectroscopy. This was accomplished by designing submicrometer-sized TiO 2 superstructures with synergistic effects of Mie and charge-transfer resonances for SERS enhancement, enabling the TiO 2 /4-mercaptobenzoic acid (MBA) system to achieve both high SERS activity and interfacial charge-transfer sensitivity. The results clearly indicate that the vibrational frequencies of MBA shift in correlation with various intermolecular interactions from hydrogen-bonding to ionic interactions. Multiple SERS analyses of NCIs were conducted for both the four DNA bases and single-stranded DNA sequences. Additionally, we performed a proof-of-concept study utilizing the relative SERS intensity to detect the relative content of two bases in single-stranded DNA sequences. This study unlocks potential applications of semiconductor SERS for exploring intermolecular-specific interactions.