Development and testing of a lab-in-a-tube biosensor

Abstract

Early detection is crucial in delivering timely treatment and improving patient outcomes. Point-of-care (POC) biosensors play an essential role in early detection, allowing for rapid and accurate diagnosis of diseases at the patient’s bedside without the need for expensive equipment or specialized personnel. By performing the analysis on-site, POC diagnostics can offer continuous monitoring and real-time data acquisition of a patient's health status. Thus, there is strong incentive in creating POC biosensors to provide healthcare professionals with greater access to diagnostic information, ultimately improving outcomes and reducing healthcare costs. Herein, the development of a POC lab-in-a-tube biosensor that utilizes simple and scalable fabrication techniques is presented. Electrodes are patterned on low-cost plastic substrates, which can be subsequently rolled and heat-shrunk into miniaturized tubing for flow-through analysis of liquid samples. Heat-shrinking of the device results in 3-dimensional, hierarchically wrinkled electrodes with morphological feature that span several orders of magnitude in size. These wrinkled electrodes demonstrate dramatically increased surface area in a given footprint compared to traditional planar electrodes. Incorporation of modified gold and silver wires allows for sensitive and stable electrochemical detection, enabling fast and quantitative results. These devices are capable of millilitre-per-minute flow rates to allow for rapid sample processing and for increased mass-transport to the electrode surface. The ability to capture analytes was characterized with nucleic acid sequences using pump-driven and blood-collection tube induced flow for rapid and accurate detection. Overall, this work demonstrates the successful development of an electrochemical platform integrated into a plastic tubing capable of rapid detection of flowing analytes. With its ease-of-use and compatibility with a wide range of flow rates, the device has the potential to be incorporated with existing medical tubing and procedures to achieve POC diagnostics.