Synthetic nanoprobes for biological hydrogen sulfide detection and imaging

Abstract

Hydrogen sulfide (H2S) is a gaseous molecule involved in multiple biological and physiological processes, including various diseases such as cancer and neurodegenerative disorders. This has led to the development of various analytical methods to monitor H2S in biological settings. Among these, fluorescence‐based assays, specifically organic small‐molecule probes, have been thoroughly utilized. They offer good sensitivity and specificity as sensors, and noninvasive detection with high spatiotemporal resolution in in vitro and in vivo imaging. Despite attempts to decrease the rate of photobleaching and enhance the photostability of these dyes, they are still limited by low survival time and complex reagent pretreatment. Fortunately, nanotechnology has been applied to develop effective, highly sensitive, and specific fluorescent nanoprobes. Specifically, nanomaterial‐based H2S probes have emerged as promising candidates for real‐time detection and imaging. In contrast to their organic molecule‐based counterparts, they offer higher versatility in imaging modes due to their unique optical properties, improved photostability and solubility within physiological fluids, as well as easily modifiable surfaces and tuneable structures for improved specificity. Recently, many nanomaterial‐based probes, ranging from inorganic nanoparticles to self‐assembled nanocomposites, have been developed. These have, for the most part, achieved sensitive and specific endogenous H2S detection and in vivo imaging. In this review, we evaluate five different nanomaterials currently being researched to detect and image endogenous H2S within the last 5 years. Furthermore, analytical methods associated with the various signal outputs, current challenges in H2S nanoprobe design, and possible future research interests are outlined and discussed.

Reactive Species-Activatable AIEgens for Biomedical Applications

“…For example, the o -diamino aromatic moiety is a recognition group for NO, and the cyclization reaction of o -diamine with NO produces a triazole moiety, which alters the electronic property and conjugation nature [ 159 , 160 , 161 ]. For H 2 S detection, the popularly used approaches include reduction of azides into amines and nucleophilic addition of H 2 S to the electrophilic group [ 162 , 163 ]. Some representative AIEgens for sensing gasotransmitters are listed Figure 13 , which show great potential for applications in biological imaging and disease diagnosis.…”

Origin of luminescence properties and synthetic methods for gold- and bimetallic gold-based nanomaterials

“…For example, an explanation for the dual emission in Au 28 (SG) 16 NCs (corrected as Au 25 in later works) could be presented after Link et al proposed their energy band structure by considering the solid-state model and molecular model for the origin of the two luminescence bands in Au 28 (SG) 16 NCs. 102 It was reported that both the radiative intraband transition (sp-sp) and the radiative interband recombination (sp-d) in the HOMO-LUMO gap contribute to the low and high energy luminescence bands, respectively.…”

“…The advantages and disadvantages of organic fluorophores vs. metal-based nanoclusters are summarized in Table 1. [15][16][17][18] Hence, recently, review articles and perspectives on metal-based nanomaterials have attracted significant attention for a wide range of applications. [19][20][21][22][23][24][25][26][27][28] Among the applications of metalbased NPs, hypoxic tumor radiotherapy is one of the most important for clinical cancer treatment.…”

Flexible wearable devices for intelligent health monitoring

“…[8][9][10][11][12][13][14][15][16][17] At present, various ingenious healthcare devices have been explored for detecting body temperature, blood pressure, heart rate and glucose based on thermoelectric effect, piezoelectric/piezoresistive mechanism, capacitive effect, or electrocatalytic/electrochemical principles. [18][19][20][21][22][23][24] Significantly, these monitoring devices can be integrated into wearable clothes or watches for continuous healthcare, which makes home-based telehealth monitoring available. [25][26][27] Therefore, to further promote the development of wearable health monitoring devices and their medical applications, this mini-review centers on the latest progress of wearable skin-like sensing devices and their applications in health monitoring, aiming to offer a panoramic review from the perspectives of health monitoring fundamentals, device construction, potential clinical applications and future outlook.…”