Urolithiasis commonly occurs in kidney and ureteral, and may cause local organ/tissue damage, even kidney failure. The incidence of this disease is increasing worldwide, in which calcium oxalate is the major composition forming the urinary calculus. Therefore, to monitor this disease for the prevention and treatment, measuring the oxalate in the urine is of great significance. Here, a rapid and sensitive colorimetric method was developed based on 3,3',5,5'-tetramethylbenzidine-manganese dioxide (TMB-MnO 2 ) nanosheets for oxalate detection. MnO 2 nanosheets acted as an efficient biomimetic oxidase to catalyze the reaction with TMB and oxalate. Pale yellow TMB can be oxidized to blue oxide TMB catalyzed by BSA-stabilized MnO 2 nanosheets, and oxalate can selectively inhibit this reaction by consuming and reacting with MnO 2 nanosheets, thus achieving the quantitative detection of oxalate. Moreover, a home-made bionic electronic-eye (E-eye) system was developed as a portable in-situ detection platform to efficiently measure the oxalate concentrations in 10 s by direct photographing. By optimizing experimental conditions, this method shows a wide linear range (7.8 μM to 250 μM) and a low detection limit (0.91 μM) for oxalate detection. Besides, this method exhibits high selectivity even with 80-fold interfering chemicals. Furthermore, the performance of the method was validated by testing the artificial urine samples, indicating its great potential for monitoring and diagnosis of urolithiasis in point-of-care applications.
Xianxin Qiu,Longjie Zhong,Ying Gan,Kaiqi Su,Shihui Hu,Ping Wang
Okadaic acid is a kind of fat-soluble diarrhetic shellfish poison existing extensively in shellfish. The rapid on site detection of shellfish contaminated by the toxin is a serious problem. Herein, a new method combining a kit with the Bionic e-Eye was developed for the rapid detection of okadaic acid on site. After optimization the kit reached a very low limit of detection, 0.19 μg L−1, and the linear detection range was 0.2–10 μg L−1. The cross reaction rate with dinophysistoxins 1 was 23.6%. The kit had a small cross reaction with other kinds of toxin like saxitoxin, gynotoxin 2 & 3 and pectenotoxins 2-b. The recovery range was about 75.78–102.56%, and the CVs were lower than 20%. A correlation analysis was conducted between the Bionic e-Eye and a microplate reader in PBS and shellfish backgrounds. The detection results of the real shellfish samples by the Bionic e-Eye exhibited great consistency with high performance liquid chromatography. The total time taken to perform the detection was less than 90 minutes. Above all, the method integrated kit with the Bionic e-Eye was very suitable for the rapid detection of okadaic acid on site.
危险品化学品经营许可证（带存储）