PVA-AWP/tyrosinase functionalized screen-printed electrodes for dopamine determination

Abstract

The development of highly sensitive amperometric biosensors for dopamine determination using commercially available SPEs in combination with the PVA-AWP photopolymer as the enzyme immobilization matrix is described in this work. This research focuses on (i) the optimization of the conditions for SPE biofunctionalization by tyrosinase entrapment in PVA-AWP and of the working conditions for dopamine determination by mathematical model application, and (ii) the evaluation of the analytical performances of the PVA-AWP/tyrosinase functionalized SPEs. Dopamine determination under optimum conditions for electrode biofunctionalization (PVA-AWP 3%, 60 min UV light exposure) andunder optimum working conditions (pH 6.5, 25 C) was performed in the dynamic concentration range of 0.9-500 mmol L À1 , 0.2-400 mmol L À1 , and 0.03-150 mmol L À1 , using respectively C SPE, MWCNT-GNP/C SPE, and graphene-GNP/C SPE. The LOD was found to be 300 nmol L À1 , 60 nmol L À1 , and as low as 10 nmol L À1 , correspondingly. The excellent analytical performances of the graphene-GNP C SPE and MWCNT-GNP C SPE were associated with their large active area (19.72 mm 2 and 15.3 mm 2 ) and enhanced electrocatalytic properties (k o ¼ 8.1 Â 10 À3 cm s À1 and 4.4 Â 10 À3 cm s À1 ) compared with the bare C SPE (12.47 mm 2 and k o ¼ 3.0 Â 10 À3 cm s À1 ). The developed biosensors were stable, reproducible, and more sensitive than most of the known biosensors for dopamine determination. They were successfully applied for dopamine determination in injections. Taking into consideration the fact that the selected enzyme immobilization approach using a water-soluble photopolymer opens the possibility of SPE biofunctionalization by photolithography, the developed biosensors are promising for fast, simple, sensitive, selective, and cost effective analysis of dopamine.

Determination of the Antioxidant Activity of Samples of Tea and Commercial Sources of Vitamin C, Using an Enzymatic Biosensor

“…It is also noteworthy that the catalytic properties of Prussian blue on the reduction of hydrogen peroxide are well known and have been discussed previously by several researchers [ 23 , 24 , 25 ].…”

“…From an analytical point of view, a greater linear range of work allows numerous alternatives for using the prototype, due to the variability of antioxidant capacities Table 1 . Linear range and similar sensitivities, in amperometric biosensors, using printed electrodes modified with PB were achieved, fixing the work potential at −100 mV [ 25 , 26 ].…”

Ultrasensitive detection of dopamine using Au microelectrodes integrated with mesoporous silica thin films

“…13 Enzyme-modified electrodes provide excellent specificity for dopamine, but they can also be limited by enzyme activity and stability. 14 Additionally, recently reported dopamine electrochemical sensors may suffer from a tedious electrode modification process and expensive instruments, though they have excellent detection performance. 15,16 Therefore, development of electrode surfaces with good antifouling capability, stability and detection sensitivity is still highly desirable.…”

Development of Enzyme Conductometric Biosensor for Dopamine Determination in Aqueous Samples

“…The way to solve the above problems is to use electrochemical biosensors. To date, there are several laboratory prototypes of biosensors for the dopamine determination, mostly based on the amperometric or voltammetric method of detection [17][18][19][20][21][22][23]. Amperometry provides such advantages as small size of equipment, easy use, fast results, high accuracy [24].…”