Lab-on-a-chip. The future is here

Measuring up to 16 biological parameters with a chip seized only 3 centimetres: is the result of a research developed by scientists at the Centro d’Investigación en Nanociencia y Nanotecnología (CIN2). This new photonic biosensor has been patented in the US and Europe.

 

 

The biosensor measures up to 16 biological parameters This development is addressed to be one of the future diagnostic technologies, the so-called lab-on-a-chip tools which will allow a person to do an analysis with a single drop of sample and to detect up to 16 parameters.

The biosensor incorporates biological receptors (enzymes, antibodies or DNA probes) which recognize the target, either bacteria, a DNA mutation or a cancer biomarker altered. “We have experimented with the sensor as a DNA probe, to identify DNA mutations, and to recognize bacteria”, explains Laura M. Lechuga, a research professor at the CSIC and coordinator of the project at the Centro d’Investigación en Nanociencia y Nanotecnología (CIN2)Centro d’Investigación en Nanociencia y Nanotecnología (CIN2). “We have applied it on serum and urine, although it could be used for other human fluids”. Also, it could be used for controlling the environmental pollution, for the fast detection of organic pollutants or pathogenic bacteria in water.

A lab in your hand

This type of sensor has attractive advantages for the health sector, as it would ensure reliable results immediately. Analysis could be done by the physician, and so it would not be necessary to send samples to the labs. It would allow relieving the overwhelmed laboratories and early medical intervention.

How could it be used in the future? As scientists imagine, the biochip would fit in a device like a smart phone, with all the electronic circuits needed to read the results. For every analysis it would be as simple as inserting a new biochip and the sample (serum or urine) on it. In some cases, such as environmental applications, the biosensor could be reused many times.

As Laura M. Lechuga explains this is highly sophisticated technology, very accurate and reliable in the measurements. The biosensor is an interferometer: it measures the optic changes in a light beam after passing through the analysed object.

Interferometers are powerful analytical tools. But adapting them to nanotechnology, to the range of the smallest, raises different issues.

Detail of some of the channels in the biosensor.Technological issues

The designed biochip has 16 interferometers. Each one is like a channel 4 micron wide and few nanometres thick, in which light beams fit. In every channel a biological receptor can be placed, therefore measuring up to 16 parameters. One of the difficulties is how to drive the macroscopic light beams (like the one emitted by a laserpoint) within these channels at nanometers range. As a solution scientists have developed a micro-grid in the entrance of every biosensor channel. 

Another issue, no less important, refers to the microfluids: how to carry microscopic quantities of the blood or urine sample to the suitable places in the biosensor, for analysis. The scientists have created an ingenious system of micro-trays, which canalize the sample to the different analysis points.

Monitoring patients, early diagnostic

¿Why measure so many parameters? One possibility is to anticipate the patient’s evolution according to different biomarkers. “We are working together with the Hepatic Unit at Hospital de la Vall d’Hebron, in Barcelona, in order to identify biomarkers of liver alteration. The goal is monitoring patients who have received a liver transplantation, to predict as soon as possible whether an infection appears and therefore the risk of rejection”.

Why measure so many parameters? One possibility is to anticipate the patient’s evolution according to different biomarkers.

Another possibility is detecting genetic mutations or protein biomarkers that are connected to the development of certain cancers, as an early diagnostic tool.  Nevertheless, warns Laura M. Lechuga, this will not be possible until the genetic mutations and biomarkers related to each disease are well known. In this respect, biomedicine has a long way to go.

Applications in other sectors are not excluded. The biosensor can be used for detection of toxins in food, pesticides in water, hormone detection (anti-doping control) or for environmental studies. In any case, the biosensor, which is already in the last stage of development, would be adapted to the need of every application.

This research has been supported for five years by Fundación Botín, within its program of Technology  transfer.

 

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