Fluorescent Determination of Succinylcholine Chloride by Naphthalimide/ Stilbazolium Dye ⊂ CP5A.

Succinylcholine Chloride (SCC), a short-acting neuromuscular relaxant, is non-fluorescent in aqueous solutions. This property makes it impossible to be determined by direct fluorescent method. Naphthalimide dye (NA) exhibits very strong fluorescence emissions in aqueous solution, after complexing with carboxylatopillar[5]arene (CP5A) in aqueous solutions, the fluorescent quenched intensity of complex was observed. On the contraty, stilbazolium dye (SA) exhibits weak fluorescence emissions in aqueous solution, after being included by CP5A, a fluorescence enhancement was observed. However, adding SCC to the NA⊂ CP5A or SA⊂ CP5A complex solution led to the recovery of the fluorescence intensity, in the meantime, the color of SA⊂ CP5A solution changed from dark yellow to light yellow. The competitive supramolecular interaction between SCC, NA and SA for CP5A was studied by spectrofluorometry, 1H NMR. Herein, a FID (fluorescence indicator displacement) system to detect SCC based on NA⊂ CP5A and SA⊂ CP5A complex was developed.

A Photochemically Active Cu2O Nanoparticle Endows Scaffolds with Good Antibacterial Performance by Efficiently Generating Reactive Oxygen Species.

Cuprous oxide (Cu2O) has great potential in photodynamic therapy for implant-associated infections due to its good biocompatibility and photoelectric properties. Nevertheless, the rapid recombination of electrons and holes weakens its photodynamic antibacterial effect. In this work, a new nanosystem (Cu2O@rGO) with excellent photodynamic performance was designed via the in situ growth of Cu2O on reduced graphene oxide (rGO). Specifically, rGO with lower Fermi levels served as an electron trap to capture photoexcited electrons from Cu2O, thereby promoting electron-hole separation. More importantly, the surface of rGO could quickly transfer electrons from Cu2O owing to its excellent conductivity, thus efficiently suppressing the recombination of electron-hole pairs. Subsequently, the Cu2O@rGO nanoparticle was introduced into poly-L-lactic acid (PLLA) powder to prepare PLLA/Cu2O@rGO porous scaffolds through selective laser sintering. Photochemical analysis showed that the photocurrent of Cu2O@rGO increased by about two times after the incorporation of GO nanosheets, thus enhancing the efficiency of photogenerated charge carriers and promoting electron-hole separation. Moreover, the ROS production of the PLLA/Cu2O@rGO scaffold was significantly increased by about two times as compared with that of the PLLA/Cu2O scaffold. The antibacterial results showed that PLLA/Cu2O@rGO possessed antibacterial rates of 83.7% and 81.3% against Escherichia coli and Staphylococcus aureus, respectively. In summary, this work provides an effective strategy for combating implant-related infections.