T.E.S.T. 2019
Contents
T.E.S.T 2019
Team T.E.S.T. is a team competing in Sensus 2019, its university is the TU Eindhoven. For Sensus 2019, T.E.S.T. investigated the possibilities for creating a biosensor which is able to measure the concentration of Adalimumab. The full TRD can be found via this link
Method
Bioluminescence
Molecular Recognition
The bioluminescent assay comprises two protein engineered and chemically modified components; tumor necrosis factor alpha (TNFα) and an anti-a dalimumab/TNFα (anti-AT) antibody (HCA204, Bio-Rad Laboratories). These components form the molecular recognition of the assay using the affinity of TNFα to adalimumab and subsequently anti-AT antibody to the adalimumab/TNFα complex (AT-complex).
Physical Transduction
The chemical reaction occurs in a microfluidic cartridge. To convert the analogue light signal into a digital signal, the emitted light from a cartridge is led through an optical setup in a cage system. First, the light from the cartridge, which is considered as a point source, is collimated by a plano-convex lens (f=25.4 mm). The emission spectrum of the bioluminescent protein has two maxima as it consists of the signal from both mNeonGreen-Nanoluc and NanoBiT. For this reason, the spectrum is split at the minimum between these maxima into a green and a blue beam. This is done through means of a long-pass dichroic mirror at 490 nm at an angle of 45 degrees. Afterwards, the green and blue beams are focused (plano-convex, f=25.4 mm) on the photodiodes (Thorlabs PDF10A, Si fW Sensitivity Fixed Gain Detector 320-1100 nm). An overview of the optical setup is given in figure 2 on the next page. The photodiodes provide an analog signal that is converted with an ADC and processed in a Raspberry-Pi comput.
Cartridge
For the sample handling a disposable cartridge with one chamber, an inlet and an outlet is used.
Reader Instrument
The used photodiodes provide an analog output signal between 0-10V. A voltage divider is used to transform the actual voltage range to the range of 0-5V. This signal is converted by the ADC (ADS1115 16-bit) to a digital signal, so it can be processed by the Raspberry Pi (3B+). The photodiodes and Raspberry Pi are powered by one power supply (Farnell RPT-60B). A 7-inch LCD touchscreen makes it possible to interact with the device.
Prizes
Analytical Performance and Creativity Award
