A Fluorescence-SERS Dual-Mode Nanoprobe for Imaging of HSP90 mRNA and Peroxynitrite in Living Cells

The dysregulation of heat shock protein 90 mRNA (HSP90 mRNA) and reactive oxygen species (ROS) is implicated in stress response and various diseases. Visualizing HSP90 mRNA and ROS dynamics is important to studying their interactions and related physiopathological mechanisms. However, effective methods for detecting both remain lacking. Herein, a covalent organic framework-based (COF-based) dual-mode nanoprobe is designed to monitor HSP90 mRNA and ONOO^- (ROS model). The nanoprobe is prepared by in situ assembly of a COF shell as the aptamer carrier on the gold nanorods (AuNRs), followed by conjugation of the ONOO^--responsive molecule, 4-mercaptophenylboronic acid (4-MPBA), to the AuNRs and modification of the HSP90 mRNA aptamer (HSP90MB) onto the COF shell. The prepared nanoprobe enables sensitive and selective fluorescence (FL) and surface-enhanced Raman spectroscopy (SERS) detection of HSP90 mRNA and ONOO^-, respectively. The dual-channel detection highlights the advantages of facilitating spectral analysis and eliminating mutual interference. In addition, the proposed strategy visualizes a positive interaction between HSP90 mRNA and ONOO^- in living cells, revealing their cellular response mechanism under stress conditions and related diseases.