A multi-functional minimally-disruptive portable electrochemical system based on yeast/Co 3 O 4 /Au/SPEs for blood lead (II) measurement.

A minimally-disruptive portable electrochemical system is constructed by combining a hand-held syringe as reservoir with disposable screen-printed electrodes (SPEs) modified with a simple and efficient yeast/Co ₃ O ₄ /Au material for lead determination by a square-wave voltammetry (SWV) method. Not only can it preserve the operation and advantages of the conventional electrochemical procedure, but it also integrates sampling, filtering and analysis to make the determination of lead convenient and effective at higher and lower concentration levels. This is the first report of a microbial biosensor based on active yeast crosslinked to Co ₃ O ₄ /Au particles using glutaraldehyde as the crosslinking agent. The determination process is simplified by introducing a fiber filter and takes only 150 s with the developed system, which illustrates its simplicity, speed and detection accuracy. Also, the design shows a wide log-linear dynamic range (LDR) from 10 ^-8 to 10 ^-14  g·L ^-1 , with a limit of detection (LOD) of 3.45 × 10 ^-15  g·L ^-1 (S/N = 3). Additionally, the proposed system was used to determine lead in blood samples, which demonstrated the potential of this biosensor for use in practical applications. Furthermore, this study provides a basis for the development of microscale blood devices for lead measurement.
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