In this study, a ratiometric strategy-based electrochemical sensor was developed by electropolymerization of thionine (THI) and β-cyclodextrin (β-CD) composite films on a glassy carbon electrode surface for imidacloprid (IMI) detection. THI played the role of an inner reference element to provide a built-in correction. In addition, the modified β-CD showed good selective enrichment for IMI to improve the sensitivity and anti-interference ability of the sensor. The current ratio between IMI and THI was calculated as the detected signal for IMI sensing. Compared with common single-signal sensing, the proposed ratiometric strategy showed a higher linear range and a lower limit of detection of 4.0 × 10−8–1.0 × 10−5 mol L−1 and 1.7 × 10−8 mol L−1, respectively, for IMI detection. On the other hand, the ratiometric strategy endowed the sensor with good accuracy, reproducibility, and stability. The sensor was also used for IMI determination in real samples with satisfactory results. The simple, effective, and reliable way reported in this study can be further used to prepare ratiometric strategy-based electrochemical sensors for the selective and sensitive detection of other compounds with good accuracy and stability.
Pu Yu,Junxiao Wang,Xiaotang Gan,Zhihua Guo,Liang Huang,Zhiping Song
Graphical Bipolar ion storage : Thionin (Thn-CH 3 COO), a biological dye, can be also used as a high-performance bipolar-type organic cathode material for aqueous rechargeable zinc batteries. In the Zn(CF 3 SO 3 ) 2 electrolyte, both CH 3 COO − and CF 3 SO 3 − anions participate the p-type reaction, while H + cation dominate the n-type reaction. Organic cathode materials (OCMs) have been widely applied in aqueous rechargeable zinc batteries (ARZBs), but there are still many novel structures to be explored for better electrochemical performance and clearer mechanism. Herein, we have studied an organic biological dye, namely thionin (Thn-CH 3 COO), as a bipolar-type OCM for ARZBs based on its electroactive phenothiazine unit. In the optimal electrolyte of 2 M Zn(CF 3 SO 3 ) 2 , Thn-CH 3 COO exhibited the lowest solubility and thus the highest cycling stability (94 % capacity retention after 100 cycles), with a reversible capacity of 162 mAh g −1 (the theoretical value is 186 mAh g −1 ) and a discharge plateau at ∼0.8 V vs. Zn 2+ /Zn. Various characterization and DFT calculations have revealed that both CH 3 COO − and CF 3 SO 3 − anions and H + cations participated the p-type and n-type reactions, respectively. In brief, the novel structure, competitive performance, and exhaustive mechanism investigation will facilitate the further development of ARZBs based on OCMs.
危险品化学品经营许可证（带存储）