Biosensors

Microfluidic cell-counting chip

whole blood → lysing buffer lyses RBCs →quenching buffer neutralizes hemoglobin from lysed cells → counting of lymphocytes and other white blood cells → capure chamber → exit counter

Used for HIV/AIDS CD4+ counting

Microcantilever biosensor

DNA oligonucleotic probes immobilized on a cantilever, target DNA hybridization causing bending of the cantilever, which can be measured to detect specific DNA sequences.

Nanopore biosensors

quantify DNA translocation through nanoscale pores by measuring ionic current changes as DNA molecules pass through.

Viral Load on a Chip

blood → metering → cell lysing → RT-LAMP amplification kit → droplets on dried primers → cell-phone fluorescence detection

higher viral loads = shorter threshold time

Microfluidic CD4+ capture chip

whole blood introduced → CD4+ cells captured via controlled flow → listed under microscope

sensitive to ~20 cells/µL in a 10 µL device volume; governed by shear stress at the chamber wall: τₗ = 6μQ / (h²w)

Biosensore from Lab to Market (Daktari-style workflow)

prick finger → apply blood drop to disposable cartridge → insert cartridge into reader unit → washing, capture, measurement → CD4 count displayed