Scientists Develop Affordable Smartphone-Based Sensor to Accurately Monitor L-Dopa Levels for Parkinson's Disease Management

Parkinson's disease is characterized by a gradual decline in neuron cells, leading to a significant reduction in dopamine levels—a neurotransmitter essential for controlling movement.

Researchers at the Institute of Advanced Study in Science and Technology (IASST), an autonomous institute under the Department of Science and Technology, have developed an innovative, affordable, and user-friendly smartphone-based sensor system designed to aid in the management of Parkinson's disease. This portable optical sensor utilizes a fluorescence turn-on mechanism to accurately detect low concentrations of L-dopa in biological fluids, a critical component in determining the appropriate dosage required for effective treatment.

Parkinson's disease is characterized by a gradual decline in neuron cells, leading to a significant reduction in dopamine levels—a neurotransmitter essential for controlling movement. L-dopa, a precursor to dopamine, is widely used as an anti-Parkinson's drug to help replenish dopamine levels. The correct dosage of L-dopa is crucial, as too much can cause severe side effects like dyskinesia, gastritis, and psychosis, while too little can result in the resurgence of Parkinson's symptoms.

Given the progressive nature of the disease and the increasing need for higher L-dopa dosages as patients age, there is a critical need for a simple, cost-effective, and rapid method to monitor L-dopa levels in the body.

The sensor developed by IASST scientists addresses this need by employing a silk-fibroin protein nano-layer, derived from Bombyx mori silk cocoons, which is coated onto reduced graphene oxide nanoparticles. This forms a core-shell structure with quantum dots that exhibit outstanding photoluminescence properties, making the sensor highly effective in detecting L-dopa in samples such as blood plasma, sweat, and urine. The system can detect L-dopa within a linear range of 5 μM to 35 μM, with detection limits as low as 95.14 nM, 93.81 nM, and 104.04 nM, respectively.

To facilitate real-time analysis, the researchers designed a smartphone-based electronic device equipped with an electric circuit connected to a 365 nm LED, powered by a 5V smartphone charger. The setup is enclosed in a dark chamber to prevent external light interference. During the sensing process, the sensor probe is illuminated by the LED, and the resulting color changes are captured using a smartphone camera. A mobile app then analyzes the RGB values from these images to evaluate the L-dopa concentration.

This groundbreaking technology provides a simple, rapid, and cost-effective tool for on-spot L-dopa detection, particularly in remote areas lacking advanced medical equipment. By accurately detecting L-dopa levels, the sensor can assist healthcare providers in adjusting dosages to ensure optimal treatment for Parkinson's disease patients, ultimately improving their quality of life.