IoT-Enabled Triglyceride Microstrip Electrochemical Sensor Using Enzymes Anchored to Gold by Polydopamine

Abstract

The accurate detection of triglycerides (fats) in the blood is useful for diagnosing cardiovascular health. This study reports a point-of-care (PoC) electrochemical assay to detect triglycerides using a IoT based smartphone-assisted platform. The assay consists of a flexible polyimide-based microstrip with electrodes composed of polydopamine (PDA)-coated gold nanoparticles (AuNPs) deposited on laser-induced graphene A coating of PDA on the AuNPs helps to anchor lipase enzymes to the electrode, resulting in an enzymatic sensor that is sensitive and specific toward triglycerides. The sensor is connected to a smartphone for data acquisition and monitoring, making it IoT-enabled for PoC applications. Because smartphones are ubiquitous, the approach presented in this paper is more compatible with PoC use than the conventional bulky sensors. The sensor had a linear response to triglyceride concentration, with a limit of detection of 17.89 mg/dL. The apparent Michaelis-Menten constant (K $_{\mathrm {appm}}$ ) of 21.6 mg/dL indicates that lipase conjugates strongly with triglyceride, resulting in a limit of quantification of 59.63 mg/dL of triglycerides in a low $2~\mu $ L of reference triglyceride solution. The validation of the test using human serum spiked with triglycerides demonstrated a recovery rate of 93.87 % of triglycerides, showing its efficacy when compared to alternative triglyceride sensors, such as metal oxides, conducting polymers, and flow injection that typically have recover rates from 90 % to 110 %. Other common analytes in the serum did not interfere with the sensing. The ability to detect triglycerides using smartphones can lead to improved personalized health monitoring.

Keywords

• Enzyme immobilization
• gold nanoparticle
• IoT
• point-of-care device
• polydopamine
• smartphone-based sensor