Researchers in Harvard & MIT has developed a facemask with a biosensor that can detect the presence of SARS-CoV-2 with the same accuracy as standard PCR tests.
Other wearables like Fitbitz, Apple watch etc use standard electronic/mechanical/optical sensors. OTOH biosensors use engineered genetic circuits to create sensors and detectors for a desired molecular target.
This team has been working for nearly three years on what's called wearable freeze-dried cell-free (wFDCF) technology and first used it with paper for ZIka & Ebola diagnostics.
These sensors enable bacteria, viruses and toxins to be detected depending on the design targets. Essentially it's a miniaturized lab on it's own - and this one is designed for Covid-19.
The sensor is freeze dried and based on CRISPR enzymes. Attached to the sensor is a sample collection pad that collects the user’s breath aerosols. When the user wears it for a minimum of 15 - 30 mins, all he has to do is press a button. This pierces a water-filled blister pack and the samples get into the sensor. The sensor contains three freeze-dried reactions, each separated by a dissolvable time delay.
First, an optimized detergent mixture disrupts any viral membranes. The second reaction is a coupled reverse transcriptase – recombinase polymerase amplification (RT-RPA) isothermal reaction, which converts the viral RNA to DNA and amplifies an area of it (the gene coding for the spike protein). The third and last reaction is the CRISPR (Cas12a) sensor, which detects the amplified DNA. There is a probe molecule that gets cleaved (cut) by the Cas12a if it is activated.
At the very end, once the sensor has been executed, the reaction flows to a lateral flow strip (similar to a pregnancy test) where the result is presented simply as a visible pattern of bands.
Note - This is a great feat of biological engineering.
It's simple, non-invasive. You wear the mask and test yourself. Moreover, unlike an antigen test, this is a nucleic acid amplification test (NAAT), which directly detects the genome of the virus. Unlike a typical PCR test, this face mask test can give results within 90 minutes without needing to send anything to a lab. And it works at room temperature, which is quite difficult task to achieve. (PCR requires heating)
Currently the cost of the sensor is about $5 and with mass production, the costs will go down for everyday use.
PS: They recently published a paper on this and copied below is the abstract if anyone cares to read.
ABSTRACT:
"Integrating synthetic biology into wearables could expand opportunities for noninvasive monitoring of physiological status, disease states and exposure to pathogens or toxins. However, the operation of synthetic circuits generally requires the presence of living, engineered bacteria, which has limited their application in wearables. Here we report lightweight, flexible substrates and textiles functionalized with freeze-dried, cell-free synthetic circuits, including CRISPR-based tools, that detect metabolites, chemicals and pathogen nucleic acid signatures. The wearable devices are activated upon rehydration from aqueous exposure events and report the presence of specific molecular targets by colorimetric changes or via an optical fiber network that detects fluorescent and luminescent outputs. The detection limits for nucleic acids rival current laboratory methods such as quantitative PCR. We demonstrate the development of a face mask with a lyophilized CRISPR sensor for wearable, noninvasive detection of SARS-CoV-2 at room temperature within 90 min, requiring no user intervention other than the press of a button."
A few photos - N95 mask with the sensor under test and the construction details.
Other wearables like Fitbitz, Apple watch etc use standard electronic/mechanical/optical sensors. OTOH biosensors use engineered genetic circuits to create sensors and detectors for a desired molecular target.
This team has been working for nearly three years on what's called wearable freeze-dried cell-free (wFDCF) technology and first used it with paper for ZIka & Ebola diagnostics.
These sensors enable bacteria, viruses and toxins to be detected depending on the design targets. Essentially it's a miniaturized lab on it's own - and this one is designed for Covid-19.
The sensor is freeze dried and based on CRISPR enzymes. Attached to the sensor is a sample collection pad that collects the user’s breath aerosols. When the user wears it for a minimum of 15 - 30 mins, all he has to do is press a button. This pierces a water-filled blister pack and the samples get into the sensor. The sensor contains three freeze-dried reactions, each separated by a dissolvable time delay.
First, an optimized detergent mixture disrupts any viral membranes. The second reaction is a coupled reverse transcriptase – recombinase polymerase amplification (RT-RPA) isothermal reaction, which converts the viral RNA to DNA and amplifies an area of it (the gene coding for the spike protein). The third and last reaction is the CRISPR (Cas12a) sensor, which detects the amplified DNA. There is a probe molecule that gets cleaved (cut) by the Cas12a if it is activated.
At the very end, once the sensor has been executed, the reaction flows to a lateral flow strip (similar to a pregnancy test) where the result is presented simply as a visible pattern of bands.
Note - This is a great feat of biological engineering.
It's simple, non-invasive. You wear the mask and test yourself. Moreover, unlike an antigen test, this is a nucleic acid amplification test (NAAT), which directly detects the genome of the virus. Unlike a typical PCR test, this face mask test can give results within 90 minutes without needing to send anything to a lab. And it works at room temperature, which is quite difficult task to achieve. (PCR requires heating)
Currently the cost of the sensor is about $5 and with mass production, the costs will go down for everyday use.
PS: They recently published a paper on this and copied below is the abstract if anyone cares to read.
ABSTRACT:
"Integrating synthetic biology into wearables could expand opportunities for noninvasive monitoring of physiological status, disease states and exposure to pathogens or toxins. However, the operation of synthetic circuits generally requires the presence of living, engineered bacteria, which has limited their application in wearables. Here we report lightweight, flexible substrates and textiles functionalized with freeze-dried, cell-free synthetic circuits, including CRISPR-based tools, that detect metabolites, chemicals and pathogen nucleic acid signatures. The wearable devices are activated upon rehydration from aqueous exposure events and report the presence of specific molecular targets by colorimetric changes or via an optical fiber network that detects fluorescent and luminescent outputs. The detection limits for nucleic acids rival current laboratory methods such as quantitative PCR. We demonstrate the development of a face mask with a lyophilized CRISPR sensor for wearable, noninvasive detection of SARS-CoV-2 at room temperature within 90 min, requiring no user intervention other than the press of a button."
A few photos - N95 mask with the sensor under test and the construction details.
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