Ion beam modified TiO ₂ nanotubular bio-interface for electrochemical detection of L-tyrosine towards smart bandage application

One of the common complications diagnosed in Diabetes Mellitus (DM) patients is Diabetic Foot Ulcers (DFUs). It is a condition wherein the deep tissues located in the lower limb undergo inflammation and infection due to neurological abnormalities (neuropathy) and various degrees of vascular diseases (angiopathy). The concentration of l-tyrosine (Tyr) rises abruptly in DFUs, and therefore may be used as an indicator for early monitoring of the patient's condition during the onset of diabetic foot disease. Herein, we report the electrochemical enzymatic detection of Tyr using low energy ion beam modified titania nanotube (TiNT) thin films with nitrogen (N⁺) and gold (Au^-) ions. Electrochemical Impedance Spectroscopy (EIS) analysis was performed to investigate the levels of Tyr using ion beam modified TiNT thin film electrodes. The modified electrodes exhibited excellent sensor performances with Au-TiNT and N-TiNT within the Tyr concentration range of 100 fM -500 μM with limit of detection (LoD)1.76 nM and 1.25 nM respectively and response time ∼ 1 min. The results indicate that low energy ion beam modified TiNT/enzyme bio-electrodes can potentially be employed as a highly sensitive and portable sensor for real-time detection of l-tyrosine in wound fluids for the development of a smart bandage.

Keywords: Diabetic foot ulcer; Electrochemical impedance spectroscopy; Gold; Nitrogen; Tyrosine.