Bleeding in the stomach or other gastrointestinal problems can now be easily detected by an ingestible sensor that has a genetically engineered bacteria that has been developed by American researchers.
The study, published in the journal Science, describes the new gadget as “bacteria-on-a-chip” where the approach combines the sensors, developed from living cells, with very low powered electronics which helps to convert the response of the bacteria into a wireless signal which is readable with a smartphone.
“By combining engineered biological sensors together with low-power wireless electronics, we can detect biological signals in the body and in near real-time, enabling new diagnostic capabilities for human health applications,” said the paper’s co-senior author Timothy Lu, an associate professor of biological engineering at Massachusetts Institute of Technology (MIT).
The sensors have been found to be working in pigs where they react with a component of the blood called theme, claims the study. Thiosulfate which is a marker of inflammation is detectable in another censor that has also been designed by the researchers.
“Our idea was to package bacterial cells inside a device,” said Phillip Nadeau, the paper’s co-lead author and a former MIT postdoc. “The cells would be trapped and go along for the ride as the device passes through the stomach.”
A probiotic strain of E. coli was first developed by the researchers which is able to create a genetic circuit that results in the bacteria to emit light at the moment that they come in contact with heme.
The bacteria were then put into four wells on the sensor especially designed for the purpose which is then layered by a semipermeable membrane allowing diffusion of molecules from the surrounding environment.
A phototransistor us placed under each well which measures the amount of light generated by the bacterial cells. That information is then relayed to a nearby wireless computer or smartphone through a microprocessor.
The data can also be analyzed through an Android app that was built by the researchers.
About 13 microwatts of power is required by the sensor that is a cylinder about 3.8 centimeters long. The sensor is estimated to be able to get power for about one and half months of continuous use form a 2.7-volt battery attached to the sensor by the researchers.
The tests of the sensors conducted on pigs have shown that they can work accurately as the researchers have bene able to detect whether any blood was present in the stomach.
“Right now, we have four detection sites, but if you could extend it to 16 or 256, then you could have multiple different types of cells and be able to read them all out in parallel, enabling more high-throughput screening,” said Nadeau.
(Adapted from Xinhuanet.com)