Scientists have invented a bio- sensor technology – known as a lab on a chip – that could be used in hand-held or wearable devices to monitor health and exposure to dangerous bacteria, viruses and pollutants.

"This is really important in the context of personalised medicine or personalised health monitoring," said Mehdi Javanmard, an assistant professor at Rutgers University-New Brunswick in the US.

"We are talking about platforms the size of a USB flash drive or something that can be integrated onto an Apple Watch, for example, or a Fitbit," said Javanmard.

The technology, which involves electronically barcoding microparticles, giving them a bar code that identifies them, could be used to test for health and disease indicators, bacteria and viruses, along with air and other contaminants.

In recent decades, research on biomarkers – indicators of health and disease such as proteins or DNA molecules – has revealed the complex nature of the molecular mechanisms behind human disease.

That has heightened the importance of testing bodily fluids for numerous biomarkers simultaneously, researchers said.

Bulky optical instruments are the state-of-the-art technology for detecting and measuring biomarkers, but they are too big to wear or add to a portable device, said Javanmard, senior author of the study published in the journal Lab on a Chip.

Electronic detection of microparticles allows for ultra- compact instruments needed for wearable devices.

The new technique for barcoding particles is, for the first time, fully electronic. That allows biosensors to shrink to the size of a wearable band or a micro-chip.

The technology is greater than 95 per cent accurate in identifying biomarkers and fine-tuning is underway to make it 100 per cent accurate, Javanmard said.

The team is also working on portable detection of microrganisms, including disease-causing bacteria and viruses.

"Imagine a small tool that could analyse a swab sample of what is on the doorknob of a bathroom or front door and detect influenza or a wide array of other virus particles," he said.

That kind of tool could be commercially available within about two years, and health monitoring and diagnostic tools could be available within about five years, Javanmard added.