Handheld biosensor detects Alzheimer’s and Parkinson’s

They have developed a handheld, non-invasive device capable of detecting biomarkers for these diseases, with the added capability of wirelessly transmitting results to a laptop or smartphone.

The device was tested on in vitro samples from patients, demonstrating accuracy comparable to existing advanced testing methods. Researchers are planning further tests on saliva and urine samples, and the device has the potential to be adapted for detecting biomarkers of other conditions.

Published in the Proceedings of the National Academy of Science on 13 November 2023, the research presents a novel approach to disease detection. The device operates on electrical detection, considered by researchers to be simpler and more accurate than chemical methods.

Ratnesh Lal, a professor at the UC San Diego Jacobs School of Engineering and one of the paper’s corresponding authors, highlighted the potential impact of this device: “This portable diagnostic system would allow testing at-home and at point of care, like clinics and nursing homes, for neurodegenerative diseases globally.”

The urgency for such a development is underscored by the projection that around 14 million Americans will suffer from Alzheimer’s Disease by 2060. Current testing methods, involving spinal taps and MRI scans, are invasive and challenging, particularly for patients with limited mobility or access to medical facilities.

Lal’s focus has been on a hypothesis linking Alzheimer’s Disease to soluble amyloid peptides forming ion channels in the brain. The new test aims to detect amyloid beta and tau peptides – biomarkers for Alzheimer’s – and alpha synuclein proteins – biomarkers for Parkinson’s – in a non-invasive manner. Lal's vision was to create a device that not only detects these biomarkers through electrical methods but also transmits the results wirelessly. This device is the culmination of his three decades of expertise and global collaboration, including co-authors from Texas and China.

“I am trying to improve quality of life and save lives,” said Lal, reflecting on his motivation behind this innovation.

The development of this device was built upon the team’s previous work during the COVID pandemic, where they had developed a similar device to detect SARS-CoV-2 virus proteins. This earlier breakthrough was facilitated by chip miniaturisation and automation of biosensor manufacturing.

The biosensor, as described in the 2023 PNAS study, is composed of a high sensitivity field effect transistor (FET) with a graphene layer and three electrodes. The device operates by detecting changes in current flow, caused by the binding of amyloids to DNA strand probes.

Initial tests with brain-derived amyloid proteins from deceased Alzheimer’s and Parkinson’s patients showed the biosensor's ability to detect specific biomarkers accurately, even at low concentrations and amidst other proteins. Although tau proteins presented detection challenges, the device's multi-biomarker approach ensures reliable results.

The technology has been licensed to biotechnology startup Ampera Life, where Lal serves as chairman. Future plans include testing blood plasma and cerebro-spinal fluid, followed by saliva and urine samples. The ultimate aim is to obtain FDA approval and market the device within a year.

This research, funded by the National Institutes of Health, the University of California San Diego, and the Chinese Academy of Sciences, utilised facilities part of the NSF-funded UC San Diego Materials Research Science and Engineering Centre, marking a significant step in the early detection and management of neurodegenerative diseases.