چكيده به لاتين
Dopamine is a key catecholamine neurotransmitter and plays an important role in the functioning of the human central nervous system. Abnormal release of dopamine can lead to various neurological disorders such as schizophrenia, Parkinson's, epilepsy, increased heart rate, arrhythmia, increased blood pressure and abnormality in the cardiovascular system. Therefore, it is very important to determine and monitor dopamine levels on a permanent basis. The measurement of dopamine in sweat can be used as a non-invasive tool to monitor the condition of patients and timely diagnosis of these disorders. Therefore, in the present study, MoSe2-FeOOH-Ag/Ag2Se heterogeneous nanozyme derived from silver-plated metal-organic framework MIL88A(Fe/Mo) has been introduced. In order to non-invasively measure dopamine in sweat, a solid-state sensor was designed and manufactured by inoculating nanozyme prepared in agarose, and the solid-state sensor was prepared for the oxidation of the tracers tetramethylbenzidine (TMB) and ortho-phenylenediamine (OPD) with pseudo-catalase and pseudo-oxidase processes, was used to create colorimetric and fluorometric signals, respectively. The presence of the target species in dopamine exposed to the colorimetric sensor caused the oxidation of dopamine and accelerated the electron transfer, causing more oxidation of TMB and intensifying the colorimetric signals. In the fluorometric sensor, the oxidation of dopamine in an alkaline medium has caused the formation of polydopamine and reduced catalytic activity and reduced the intensity of the fluorometric signal. Sensor operational variables such as response time, pH, nanozyme concentration, tracer concentration and oxidizing agent concentration were optimized to achieve the best result, the best responses were in 20 and 30 minutes, 3 and 7 pH, 0.09 and 0.3 w/v, 0.33 and 1.2 mM tracer concentration and 0.45 , 0.47 % respectively, were obtained for colorimetric and fluorometric sensors. A linear range of 1-700 and 3-700 μM, with detection limits of 0.3 and 0.9 μM was obtained for colorimetric and fluorometric sensors, respectively. The proposed sensor shows a favorable selectivity over similar species. Also, the deviation of the desired standards of 1.7 and 1.4 was obtained for colorimetric and fluorometric sensors, respectively. The designed sensors were successfully used to measure dopamine in a real artificial sweat sample with a recovery percentage of 94.5-102.40. The results emphasize that the designed sensors provide the possibility of non-invasive evaluation of important biological species in real samples for human health monitoring.
