Facile Non‐enzymatic Lactic Acid Sensor Based on Cobalt Oxide Nanostructures

Abstract

In this study, we have investigated the effect of counter anions on the morphology of cobalt oxide nanostructures. The nanostructures of cobalt oxide are prepared by a low temperature aqueous chemical growth method. The morphology of cobalt oxide nanostructure material was investigated by scanning electron microscopy and the crystalline structure was studied by powder X‐ray diffraction technique. The cobalt oxide nanostructures exhibit the nanowire, lump, bundle of the nanowire and flower‐like morphologies. The XRD study has revealed a cubic phase of cobalt oxide nanostructures. The electro‐catalytic properties of cobalt oxide nanostructures were explored through cyclic voltammetry and amperometric techniques by sensing of lactic acid in the alkaline media. The cobalt oxide nanostructures prepared from cobalt nitrate have shown a well‐resolved redox peak. The proposed mechanism for the non‐enzymatic lactic acid sensor is elucidated by considering the morphology and cyclic voltammetry response. The limit of detection for the sensor was found to be 0.006 mM and it exhibits a linear range from 0.05–3 mM of lactic acid as shown by cyclic voltammetry. The amperometric response has shown the excellent current‐concentration response and the linear range of sensor was found to be 0.1 mM to 5.5 mM. The lactic acid sensor is stable, selective and can be used for practical applications. This study provides an excellent alternative analytical tool for the determination of lactic acid.

What Is Left for Real-Life Lactate Monitoring? Current Advances in Electrochemical Lactate (Bio)Sensors for Agrifood and Biomedical Applications

“…In the first place, specific features of nanomaterials are exploited to promote lactate oxidation mechanism over other species. For example, Change et al proposed a non-enzymatic lactate sensor by using cobalt oxide nanostructures [ 51 ]. The authors indicated that the material possessed Co 2+ and Co 3+ centres while the material was embedded in solution.…”

Recent Advances in Wearable Biosensors for Non-Invasive Detection of Human Lactate

“…The amperometric lactate biosensor detects the current by applying a specific voltage between the working electrode and the reference electrode, and the measured current is proportional to the concentration of analyte in the solution for quantitative analysis [ 21 , 47 ]. Compared with other types of electrochemical biosensors, the amperometric type can simultaneously measure multiple substances and reflect the content of the analyte more intuitively and has the advantage of being disposable.…”

“…Since the regulation of human lactate during secreting process keeps its concentration within a small fluctuation range, highly sensitive sensors are required to capture the small physiological related concentration fluctuations [ 20 ]. In order to improve the sensitivity of the sensor, researchers applied metal oxides [ 21 , 22 , 23 , 24 , 25 , 26 ], carbon nanotubes (CNTs) [ 27 ], graphene [ 28 , 29 ], novel two-dimensional materials (e.g., MXene) [ 30 , 31 ]. and porous materials (e.g., MOFs) [ 32 , 33 , 34 ] to various types of lactate biosensors.…”

A non-enzymatic electrochemical sensor composed of nano-berry shaped cobalt oxide nanostructures on a glassy carbon electrode for uric acid detection

“…18,19 Among transition metal oxides, nanostructures of Co 3 O 4 have been utilized in the nonenzymatic sensing of different biomolecules due to their catalytic activity in mild conditions. [20][21][22][23][24] For example, Kogularasu et al reported the use of Co 3 O 4 polyhedrons to fabricate nonenzymatic electrochemical sensors for detecting hydrogen peroxide. 20 Zhang and Liu utilized Co 3 O 4 nanosheets for the non-enzymatic detection of glucose.…”

“…23 Chang et al evaluated the effect of Co 3 O 4 nanostructures on lactic acid-sensing. 24 However, there is no report on the use of nano-berry shaped Co 3 O 4 nanostructures to detect uric acid.…”