Luminescent gold nanocluster-based sensing platform for accurate H2S detection in vitro and in vivo with improved anti-interference

Abstract

Gold nanoclusters (Au NCs) are promising luminescent nanomaterials due to their outstanding optical properties. However, their relatively low quantum yields and environment-dependent photoluminescence properties have limited their biological applications. To address these problems, we developed a novel strategy to prepare chitosan oligosaccharide lactate (Chi)-functionalized Au NCs (Au NCs@Chi), which exhibited emission with enhanced quantum yield and elongated emission lifetime as compared to the Au NCs, as well as exhibited environment-independent photoluminescence properties. In addition, utilizing the free amino groups of Chi onto Au NCs@Chi, we designed a FRET-based sensing platform for the detection of hydrogen sulfide (H2S). The Au NCs and the specific H2S-sensitive merocyanine compound were respectively employed as an energy donor and acceptor in the platform. The addition of H2S induced changes in the emission profile and luminescence lifetime of the platform with high sensitivity and selectivity. Utilization of the platform was demonstrated to detect exogenous and endogenous H2S in vitro and in vivo through wavelength-ratiometric and time-resolved luminescence imaging (TLI). Compared to previously reported luminescent molecules, the platform was less affected by experimental conditions and showed minimized autofluorescence interference and improved accuracy of detection.

Biomedical Applications for Gold Nanoclusters: Recent Developments and Future Perspectives

“…The vancomycin stabilized gold nanoclusters (Van-AuNCs) were designed and synthesized by Yu et al for detection of Fe 3+ in tap water, lake water, river water, and sea water as one of its application in environmental sample analysis [ 66 ]. Chitosan-functionalized gold nanoclusters (AuNCs@Chi) were produced and developed for the use as a detecting material of hydrogen sulfide (H 2 S) employing Förster resonance energy transfer (FRET) mechanism [ 67 ]. The reason for the researchers to detect H 2 S is that hydrogen sulphide is involved in many biological processes which include vasodilation [ 68 , 69 ], anti-inflammation [ 70 , 71 ], and neurotransmission [ 72 ].…”

Engineering Intelligent Nanosystems for Enhanced Medical Imaging

“…While many efforts are dedicated to sensing pH and hydrogen peroxide, many more biomedically relevant analytes may be measured, such as levels of ions, [63,[234][235][236][237] reactive oxygen or nitrogen species, [238][239][240][241][242][243][244][245][246] enzymes, [81,[247][248][249][250][251][252][253][254] glutathione, [255][256][257][258][259][260] and other biomarkers. [261][262][263] An example is the ratiometric hypochlorite sensor developed by Zou et al for the detection of arthritis ( Figure 11A). [264] These upconversion nanoparticles can be excited at 980 or 808 nm, and the absorbance of the latter wavelength is mediated by a fluorescent dye on the particles.…”

Metal Nanoclusters–Based Ratiometric Fluorescent Probes from Design to Sensing Applications

“…Hydrogen sulfide (H 2 S), as a novel gaseous signaling molecule, plays an important role in mediating a wide range of physiological effect in cardiovascular, neuronal, immune, endocrine, and gastrointestinal systems . A novel design strategy to prepare chitosan oligosaccharide lactate (Chi)‐functionalized Au NCs (AuNCs@Chi) was implemented for ratiometric sensing and time‐resolved fluorescence imaging of H 2 S by Huang group, which possess high quantum yield, elongated emission lifetime, and environment‐independent photofluorescence properties as compared to the AuNCs. The sensing mechanism was based on FRET process between the Au NCs acted as an energy donor and specific H 2 S‐sensitive merocyanine compound acted as an energy acceptor.…”