Redox-responsive inorganic fluorescent nanoprobes for serodiagnosis and bioimaging

Redox reactions play fundamental roles in life and are at the core of metabolism. Thus, observing and quantifying these reactions is crucial for diagnostics and therapy. Recent advances in inorganic fluorescent nanoprobes have revolutionized the field, enabling in vitro diagnostics by providing reliable tools for real-time, quantitative determination of redox biomolecule levels in biological samples and cells. Due to their high stability, these probes are also widely used in bioimaging, providing real-time information for in vivo diagnostics and guiding treatment of diseases associated with redox biomolecules. This review explores the diverse landscape of inorganic fluorescent nanoprobes designed for the detection of biologically relevant reactive oxygen and nitrogen species. The discussion is divided into several sections, each focusing on nanoprobes tailored for specific oxidative species. The impact of tailored nanoprobes in diagnostics and imaging-guided treatment depends on their chemical composition, surface property, and fluorescence mechanism. The discussions highlight the current strengths and weaknesses, which will help to design more efficient redox-responsive inorganic fluorescent nanoprobes in the future.