low-cost sensor detects early-stage of Parkinson's disease

An electrochemical sensor that can identify Parkinson's disease at various stages has been created by researchers at the Federal University of So Carlos (UFSCar) and the University of Campinas (UNICAMP) in Brazil. The gadget was created using a standard 3D printer and showed early disease detection capabilities, serving as a model for the detection of other diseases, according to the study.

Findings in the journal published in the journal Sensors and Actuators B: Chemical.

"The sensor rapidly indicates the level of the protein PARK7/DJ-1 in human blood and synthetic cerebrospinal fluid. The molecule is associated with Parkinson's at levels below 40 micrograms per liter [40 mg/L]," said Cristiane Kalinke, first author of the article.

Kalinke is a postdoctoral fellow at UNICAMP's Institute of Chemistry (IQ) and a visiting researcher at Manchester Metropolitan University in the United Kingdom.

"It can be printed in various shapes and sizes. It can also be miniaturized to create a genuinely portable device that requires a very small sample," she explained.

To build the sensor, the researchers used a commercial filament made basically of polylactic acid (PLA), a biodegradable polymer, associated with a conductive material (graphene) and other additives. Three electrodes printed on the plastic substrate by additive manufacturing were chemically treated to make them more conductive and stimulate formation of a surface layer of functional groups (carboxyls) that bind to antibodies.

The activation process entailed removal of the polymeric insulating surface from the electrodes by immersion in sodium hydroxide (NaOH) and application of an electric potential (positive and negative). A reaction was then promoted between antibodies and PARK7/DJ-1 to produce a diagnosis. Specific antibodies for PARK7/DJ-1 were immobilized on the surface of the electrodes, and the sensor was used to detect the protein at three levels: 30 mg/L, 40 mg/L and 100 mg/L. The average level in patients diagnosed with Parkinson's at different stages is approximately 30 +- 9 mg/L, according to data in the scientific literature.

"Patients are highly unlikely to go to see a doctor for a routine exam to detect early-stage Parkinson's. If onset of the disease is suspected, physical and behavioral symptoms have probably appeared, and the disease is probably already well-established," said Juliano Alves Bonacin, last author of the article and a professor in the Department of Inorganic Chemistry at IQ-UNICAMP. "We decided to design and produce a very simple device that was cheap and could be used for continual monitoring, with alerts for physicians and patients if there were alterations in the level of PARK7/DJ-1, which is especially useful when analyzed in conjunction with other biomarkers."