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A Wearable Sensor for Hormones Based on a Native Microbial Sensing

Periodic Reporting for period 2 - SENSHOR (A Wearable Sensor for Hormones Based on a Native Microbial Sensing)

Reporting period: 2019-03-15 to 2020-03-14

Connected devices that monitor human biology in real-time represent the next frontier in biosensors. Monitoring hormones is of significant interest as hormones play critical roles in multiple physiological processes including stress adaptation, blood pressure control, reproductive rhythms, and body odor. However, the real-time monitoring of hormones is challenging from a biological, chemical, and engineering perspective. We are designing and developing a novel sensor for progesterone. Our approach combines microbial genomics, protein engineering, new polymer and nanoparticle compositions, and sensor design. The biosensor is composed of a hormone-sensitive transcription factor (TF) and DNA, both fluorescently labelled. Without the hormone, the DNA binds the TF, inducing fluorescence resonance energy transfer (FRET), resulting in fluorescence from both the TF and DNA. In the presence of progesterone, the DNA and TF separate, terminating energy transfer, resulting in emission only from the donor.
The overall objective is to obtain a stable and reversible sensor that allow the detection of progesterone at nanomolar levels.
We have developped a fluorescent sensor based on FRET to detect progesterone in solution. The sensor is composed of Quantum Dots, Transcription Factors and oligonucleotides. So far, the results we obtained are :
- stable and bright Quantum Dots in water
- optimization of the limit of detection of the sensor to 15 nM of progesterone
- reversibility of the sensor and use on a bench top device to read directly in artificial urine
- modelization of the sensors to identify the key parameters
- optimization of the optical properties by changing the nature of the donor and acceptor dyes for the FRET system.
The biosensor we developped based on Transcription Factors is a novel type of sensors. Actual sensors are limited by the nature of the biological recognition elements (aptamers, antibodies, enzymes) and are usually expensive to produce and do not allow continuous measurements. Using bacteria parts (Trasncription Factors) as a novel biological sensing element open a new field in biosensors. We have proven that those biosensors are reversible and can be read on cheap bench-top devices. The next step is to prove that they can be wear for continuous sensing. Continuous hormones biosensors could help women fertility disorders (progesterone), human behaviour (testosterone), endocrinal disrupters tracking etc.

For the last year of the project, we started to develop two projects :
- dynamic micelles based on polypeptides and DNA for protein detection.
- in situ synthesis and nanoparticles formation of amphiphilic polypeptides-based polymers
Biosensor principle