The reliable and fast determination of lactate sensor has attracted continuous attention in the past few decades due to its considerable applications. Most research in the development of amperometric lactate biosensors has focused on enzymatic sensor that is electrode treated with lactate-active enzyme due to its biological selectivity. Despite this advantage, enzyme- immobilized biosensor has still suffered from the short-term stability because of loss of enzyme activity over time induced by biofouling and biodegradation. Alternatively, non-enzymatic lactate sensor has been proposed employing earth-abundant materials that are biologically stable as well as electrochemically active to lactate. However, the lower sensitivity of non-enzymatic approach than enzymatic one are still problematic, thus should be addressed in order to bring it to commercialization.<br/>Here, we propose a highly sensitive non-enzymatic lactate biosensor using porous nickel oxide nanostructure as providing more pathway for direct electrons transfer between the redox stages and electrode surface. Porous nanostructure of nickel oxides are fabricated employing sol-gel based inverse micelle method with different calcination temperature from 250 to 450 celsius degree in order to control microstructural characteristics. Lactate sensitivity of nickel oxide with different porosity are also assessed using cyclic voltammetry (CV). As a result, nickel oxide electrode calcined at 350 celsius degree displayed excellent performance in terms of sensitivity, response rate and selectivity. It offered a wide dynamic detection range of 0.01-27.76 mM as well as selective detection of lactate in the presence of several interferences such as ascorbic acid, dopamine and uric acid. Furthermore, the proposed electrodes also exhibit high sensitivity of 80.763 µA/mMcm<sup>-2</sup>, low detection limit of 0.42 mM, respectively, which are comparable to those of enzymatic lactate sensors reported previously. In addition, we also explored microstructural and chemical characteristics with different calcination temperature using various characterization methods such as Brunauer-Emmett-Teller (BET), FT-IR, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), thus revealed the origin of best performance in nickel oxide calcined at 350 celsius degree.

Highly sensitive non-enzymatic lactate biosensor driven by porous nanostructured nickel oxide

256th National Meeting (2018)

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