Journal des techniques analytiques et bioanalytiques

Abstrait

A Portable Microcontrolled Pumping Flow System Developed to In Loco Determination of Diuron at Nanomolar Levels Employing a Disposable Biosensor

Bruno C Janegitz, Fernando Campanhã Vicentini, Vagner B dos Santos, Thiago B Guerreiro and Orlando Fatibello-Filho

Microcontrolled systems coupled biosensors have attracted attention. Here, we describe an automated and portable microcontrolled pumping flow system (μC-PFS) developed to biosensing application. The flow system is fully automatic, portable, it works in battery module and it dispenses the use of microcomputer and the manual operations. This device presents mainly a microcontroller as central processing unit (CPU), an aquarium air pump and three-way solenoid valves to propulsion and the volume control of aliquots inserted in the flow system. Once available its performance, this device was used to pump samples and solution towards a compacted and miniaturized electrochemical flow cell (EFC) employing a multicommutated flow procedure. In the EFC, it was used a biosensor based on acetylcholinesterase immobilized on the gold nanoparticles modified-screen printed carbon electrode, which was used in order to perform the determination of diuron by enzymatic inhibition employing a chronoamperometry. Under the best experimental conditions, the calibration curve for diuron determination was linear in the concentration range from 80 to 1400 nmol/L with a detection limit of 50 nmol/L. Moreover, the proposed system was fully automated, showed precise, with low consumption of sample and waste generation with an analytical throughput of 13/h.