Project Lead(s): Nitin Kale
Myocardial infarction (MI) is difficult to detect in the early stages.
Due to delayed and uncertain diagnosis, physicians are often unable to take treatment decisions during the ‘golden hour’, i.e., before commencement of necrosis. These delays can cause incapacitation or death.
The project team set out to build a smart instrument that could rapidly diagnose an MI.
The instrument would enable a physician to arrive at a treatment decision very early and would even be suitable for use by a qualified nurse at a rural healthcare centre in India.
The device employs a microcantilever-based biosensing system to detect early cardiac markers (e.g., myoglobin) that are released in the blood after an MI.
Antibodies to specific antigens that the team are attempting to detect are immobilized on the surface of a cantilever. In the presence of a specific antigen, the microcantilever deflects, due to surface stress changes caused by bio-molecular recognition.
Mechanical movement of the cantilever is converted into an electrical signal by a piezoresistor embedded inside the cantilever, which is detected by ultra-sensitive electronics.
The team has managed to optimize the different components necessary to develop a working prototype for what they are calling an Instrument for Ultra-Sensitive and Rapid Detection of Myocardial Infarction among Rural Populations.
Achievements of the project were as follows:
· successful fabrication of piezoresistive microcantilevers
· successful surface functionalization and biomolecule immobilization
· fabrication of a rudimentary fluid cell to house the cantilever die
· isolation of electrical contacts from the fluid flow path, to ensure that the resistors do not short
· development of a ‘frugally-engineered’ bio-chip that consists of the functionalized cantilevers, fluid cell, PCB/connectors and the liquid inlet/outlet.
The experimental set-up (consisting of biochip, syringe pump and detection electronics) was then integrated.
Intelligent experiments were designed to check the stability of the cantilevers’ resistance in liquids, tests with general proteins and, finally, tests with cardiac proteins.
Cardiac proteins (such as hIgG, myoglobin in spiked PBS and spiked serum) were detected with the cantilevers and electronic instrumentation.
The project team intends to apply for scale-up funding from Grand Challenges Canada.