Yongkang Li,Feitong Ren,Jiayin Li,Yao Chen,Jun Liu,Chun Yang
Chloramphenicol (CAP) has demonstrated favorable therapeutic effects against various bacteria and is widely utilized in the aquaculture industry. However, CAP has recently been classified as a carcinogen, emphasizing the importance of developing effective methods to monitor its concentration. In this study, one-dimensional/two-dimensional (1D/2D) SnO 2 /reduced graphene oxide (rGO) composites were employed to modify a glassy carbon electrode (GCE) for the electrochemical detection of CAP. The SnO 2 /rGO composite materials were synthesized via a solution reaction and calcination method. Optimal electrochemical sensing conditions, including pH values, scan rates, and accumulation parameters, were systematically investigated to demonstrate feasibility. The resulting SnO 2 /rGO/GCE achieved a current density of 154.56 µA/cm², up to 75 times higher than other modified electrodes. Furthermore, the SnO 2 /rGO/GCE exhibited a strong linear relationship within a detection range of 0.001–100 μM and an excellent limit of detection of 0.315 nM for CAP. Finally, the electrodes with optimized modifications were successfully applied to determine CAP concentrations in real lake water and milk samples. These promising results suggest that the as-fabricated SnO 2 /rGO electrode presents a novel and highly effective approach for CAP detection.
Yukun Wang,Hanyin Zhang,Renzong Hu,Jiangwen Liu,Teunis van Ree,Haihui Wang,Lichun Yang,Min Zhu
A ternary composite of Fe 3 O 4 /SnO 2 /rGO has been synthesized via a facile one-step hydrothermal method . In the composite, rGO serves as a conductive and robust matrix, Fe 3 O 4 and SnO 2 nanoparticles are uniformly loaded on the rGO nanosheets without aggregation, due to the space-confine effect of the simultaneous nucleation and growth of Fe 3 O 4 and SnO 2 nanocrystallites . As an anode material for lithium-ion batteries, the Fe 3 O 4 /SnO 2 /rGO nanocomposite exhibited a reversible capacity of 947 mAh g −1 at a current density of 200 mA g −1 in the first cycle, and maintained 831 mAh g −1 after 200 cycles. The cyclic performance and rate capability of the Fe 3 O 4 /SnO 2 /rGO are markedly improved compared with the binary counterparts of FeO x /rGO and SnO x /rGO obtained in the control experiment, as a result of enhanced structural stability and kinetics for charge and Li + transfer due to the synergetic effect in the ternary composite.
Wang Yingyi,Liu Lin,Sun Fuqin,Li Tie,Zhang Ting,Qin Sujie
This study reported a novel humidity-insensitive nitrogen dioxide (NO2) gas sensor based on tin dioxide (SnO2)/reduced graphene oxide (rGO) composites through the sol-gel method. The sensor demonstrated ppb-level NO2 detection in p-type sensing behaviors (13.6% response to 750 ppb). Because of the synergistic effect on SnO2/rGO p-n heterojunction, the sensing performance was greatly enhanced compared to that of bare rGO. The limit of detection of sensors was as low as 6.7 ppb under dry air. Moreover, benefited from the formed superhydrophobic structure of the SnO2/rGO composites (contact angle: 149.0°), the humidity showed a negligible influence on the dynamic response (Sg) of the sensor to different concentration of NO2 when increasing the relative humidity (RH) from 0 to 70% at 116°C. The relative conductivity of the sensor to 83% relative humidity was 0.11%. In addition, the response ratio (Sg/SRH) between 750 ppb NO2 and 83% RH was 649.0, indicating the negligible impaction of high-level ambient humidity on the sensor. The as-fabricated humidity-insensitive gas sensor can promise NO2 detection in real-world applications such as safety alarm, chemical engineering, and so on.