Electrospun Cu-doped In_(2)O_(3) hollow nanofibers with enhanced H2S gas sensing performance

One-dimensional nanofibers can be transformed into hollow structures with larger specific surface area, which contributes to the enhancement of gas adsorption. We firstly fabricated Cu-doped In_(2)O_(3) (Cu-In_(2)O_(3)) hollow nanofibers by electrospinning and calcination for detecting H2S. The experimental results show that the Cu doping concentration besides the operating temperature, gas concentration, and relative humidity can greatly affect the H2S sensing performance of the In_(2)O_(3)-based sensors. In particular, the responses of 6%Cu-In_(2)O_(3) hollow nanofibers are 350.7 and 4201.5 to 50 and 100 ppm H2S at 250 ℃, which are over 20 and 140 times higher than those of pristine In_(2)O_(3) hollow nanofibers, respectively. Moreover, the corresponding sensor exhibits excellent selectivity and good reproducibility towards H2S, and the response of 6%Cu-In_(2)O_(3) is still 1.5 to 1 ppm H2S. Finally, the gas sensing mechanism of Cu-In_(2)O_(3) hollow nanofibers is thoroughly discussed, along with the assistance of first-principles calculations. Both the formation of hollow structure and Cu doping contribute to provide more active sites, and meanwhile a little CuO can form p–n heterojunctions with In_(2)O_(3) and react with H2S, resulting in significant improvement of gas sensing performance. The Cu-In_(2)O_(3) hollow nanofibers can be tailored for practical application to selectively detect H2S at lower concentrations.

A visual photothermal paper sensor for H_2S recognition through rational modulation LSPR wavelength of plasmonics

It is known that the localized surface plasmon resonance(LSPR) wavelength of plasmonics is highly dependent on compositions and geometry of plasmonics as well as the surrounding environments. Here, monodispersed Au@Ag core-shell nanoparticles(Au@Ag NPs) were prepared by carefully optimizing the shell thickness of Au@Ag NPs, and the presence of hydrogen sulfide(H_2 S) would significantly alter the LSPR wavelength. On the basis of this, a photothermal paper sensor for on-site recognition of H_2 S was constructed with a visual detection limit of 12.8 ng/L.

A near-infrared fluorescent probe for monitoring fluvastatin-stimulated endogenous H_2S production

Most reported fluorescent probes have limitations in practical applications in living systems due to the strong autofluorescence background,construction of probes with near-infrared（NIR） fluorescence emission is an accessible approach for addressing this challenge.We here designed a NIR fluorescent probe for monitoring the endogenous production of H2S in living cells.The designed probe showed significant NIR fluorescence turn-on response to H2S with high selectivity,enabling the sensitive detection H2S.Importantly,the probe could be applied in monitoring the endogenous production of H2S in raw 264.7 macrophages.This study showed that fluvastatin can promote the activity of cystathionineγ-lyase（CSE） for generation H2S.