title: Lactate Sensors on Flexible Substrates.
abstract: Lactate detection by an in situ sensor is of great need in clinical medicine, food processing, and athletic performance monitoring. In this paper, a flexible, easy to fabricate, and low-cost biosensor base on lactate oxidase is presented. The fabrication processes, including metal deposition, sol-gel IrOxdeposition, and drop-dry enzyme loading method, are described in detail. The loaded enzyme was examined by scanning electron microscopy. Cyclic voltammetry was used to characterize the sensors. Durability, sensibility, and selectivity of the biosensors were examined. The comparison for different electrode sizes and different sensing film materials was conducted. The sensor could last for four weeks with an average surface area normalized sensitivity of 950 nA/(cm² mM) and 9250 nA/(cm² mM) for Au-based electrodes, and IrOx-modified electrodes respectively, both with an electrode size of 100 × 50 μm. The self-referencing method to record noises simultaneously with the working electrode greatly improved sensor sensitivity and selectivity. The sensor showed little response to interference chemicals, such as glutamate and dopamine.
authors.affiliation: Electrical Engineering, University of Texas‒Arlington, Arlington, TX 76019, USA. xuesong.yang@mavs.uta.edu.
authors.forename: Xuesong
authors.initials: X
authors.lastname: Yang
authors.affiliation: Texas A&M Health Science Center, Bryan, TX 77807, USA. timwfu@gmail.com.
authors.forename: Timothy
authors.initials: T
authors.lastname: Fu
authors.affiliation: Electrical Engineering, University of Texas‒Arlington, Arlington, TX 76019, USA. pavankumar.kota@mavs.uta.edu.
authors.forename: Pavan Kumar
authors.initials: PK
authors.lastname: Kota
authors.affiliation: Electrical Engineering, University of Texas‒Arlington, Arlington, TX 76019, USA. maggie.tjia@mavs.uta.edu.
authors.forename: Maggie
authors.initials: M
authors.lastname: Tjia
authors.affiliation: Electrical Engineering, University of Texas‒Arlington, Arlington, TX 76019, USA. nmanhcuong@gmail.com.
authors.forename: Cuong Manh
authors.initials: CM
authors.lastname: Nguyen
authors.affiliation: Electrical Engineering, University of Texas‒Arlington, Arlington, TX 76019, USA. jcchiao@uta.edu.
authors.forename: Jung-Chih
authors.initials: JC
authors.lastname: Chiao
keywords: IrOx; biosensor; flexible substrate; lactate