Ultrastable Gold Nanoparticles-Based Nanoplatform with Mitochondria Targeting and High-Fidelity Intracellular Bioimaging Enterokinase Levels

Abstract

Mitochondria are key organelles in mammalian cells whose dysfunctions are linked to various diseases. Numerous gold nanoparticles functionalized with lipophilic cation categories via Au-S bond for mitochondria targeting have been reported. However, cleavage of the Au-S bond by biothiols and other chemicals is a long-standing problem hindering practical applications, especially for intracellular detection and bioimaging. Herein, we report a mitochondria-targeting AuNP-based nanosensor with negatively charged peptide modification. Furthermore, we directly introduce the peptide motif via diselenide-modified AuNPs instead of traditional Au-S bonds . In vitro and living cell-based assays show that our designed strategy is simple to prepare, but ultrastable under thiol-rich physiological conditions. Furthermore, we have demonstrated that the nanosensor AuNP@DSe-Plinker TMR can monitor enterokinase (ENTK) levels in the mitochondria of HeLa cells with a high-fidelity fluorescent signal under physiological conditions, thus pr oviding a new idea for the design and preparation of ultrastable AuNP-based nanosystem .

Keywords: Gold nanoparticles, ENTK, mitochondria targeting, negative charge peptides, high-fidelity bioimaging