Electrochemical detection and quantification of lithium ions in authentic human saliva using LiMn2O4-modified electrodes

Journal article

We report an electrochemical sensor for the detection of lithium ions (Li+) in authentic human saliva at lithium manganese oxide (LiMn2O4)-modified glassy carbon electrodes (LMO-GCE) and screen-printed electrodes (LMO-SPE). The sensing strategy is based on an initial galvanostatic delithiation of LMO followed by linear stripping voltammetry (LSV) to detect Li+ in the analyte. The process was investigated using powder X-ray diffraction (PXRD) and voltammetry. LSV measurements reveal a measurable lower limit of 50.0 µM in both LiClO4 aqueous solutions and synthetic saliva samples, demonstrating the applicability of the proposed analytical method down to low Li+ concentrations. Four different samples of authentic human saliva were then analysed with the established sensing strategy using LMO-SPE, showing good linearity over a concentration range up to 5.0 mM Li+ with high reproducibility (RSD <7%) and applicability for routine monitoring purposes. The total time needed to analyse a sample is less than 3 min.

Authors: Suherman, A; Rasche, B; Godlewska, B; Nicholas, P; Herlihy, S

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: ACS Publications
• Journal: ACS Sensors
• Volume: 4
• Issue: 9
• Pages: 2497–2506
• Publication date: 2019-08-20
• Acceptance date: 2019-08-20
• DOI: 10.1021/acssensors.9b01176
• ISSN: 2379-3694
• Pmid: 31429259
• Language: English
• Keywords: LiMn2O4; lithium; galvanostatic delithiation; linear sweep voltammetry; screen-printed electrode; authentic human saliva