Scientists have developed an affordable, user-friendly, portable smartphone-based fluorescence turn-on sensor system that can aid in the management of Parkinson's disease. The sensor will help in accurately detecting the concentration of L-dopa in the body, helping in determining the exact dosage required for effective control of the disease.
Parkinson's disease is marked by a continuous decrease in neuron cells, which leads to a significant decrease in the levels of dopamine (neurotransmitter) in our body. L-dopa is a chemical that gets converted into dopamine in our body and hence acts as anti-Parkinson's drugs.
It helps to compensate for the lack of dopamine. As long as the right amount of L-dopa is given, the disease can be controlled. However, due to the progressive nature of Parkinson's, as the patient ages, more L-dopa is needed to compensate for the continued loss of neurons.
However, too high a dose of L-dopa can cause serious side effects, such as dyskinesia, gastritis, psychosis, paranoia, and orthostatic hypotension, while too low a dose can cause Parkinson's symptoms to regress.
Considering the important role of optimal levels of L-DOPA in medicine, it is essential to develop a simple, cost-effective, sensitive, and rapid method for monitoring L-DOPA in biological fluids.
Recently, the Institute of Advanced Study on Science and Technology (IASST), an autonomous institute of the Department of Science and Technology, has developed an affordable, user-friendly, portable smartphone-based optical sensor system using fluorescence turn-on mechanism for instantaneous detection of low levels of L-DOPA in biological samples.
This sensor is fabricated by coating silk-fibroin protein nano-layers obtained from Bombyx mori silk cocoons on the surface of reduced graphene oxide nanoparticles. This system forms core-shell graphene-based quantum dots with excellent photoluminescence properties, making it an effective fluorescent turn-on sensor probe for detecting L-dopa in real samples such as blood plasma, sweat and urine within the linear range of 5 μM to 35 μM. The corresponding detection limits were determined to be 95.14 nM, 93.81 nM and 104.04 nM, respectively.
The researchers have designed a smartphone-based electronic device that has an electric circuit connected to a 365nm LED powered by a 5V smartphone charger. The entire setup is immersed in a dark chamber to isolate it from external light. Visual colour changes were observed during the sensing process by illuminating the sensor probe with a 365nm LED and capturing images with a smartphone camera. The RGB values from the images are used to evaluate L-dopa concentrations using a mobile app. This simple, cost-effective and rapid screening tool is important for on-spot analyte detection in remote areas lacking advanced equipment.
This sensor can help adjust the dosage required for effective control of the disease by detecting whether the level of L-dopa is low in the biological samples of the patient.
Publication link: https://doi.org/10.1016/j.pneurobio.2006.11.009
Shape 1: A simple, biocompatible synthesis route for the growth of aspartic acid-reduced graphene oxide core-shell quantum dots decorated with silk fibroin. This fluorescence nanoprobe is used for smartphone-based rapid sensing of L-dopa in aqueous media and real