The ability to perform biological laboratory operations via biomolecular recognition in miniaturized (lab-on-a-chip) devices has many technological, economic and social benefits: reduction of the time and cost of the analysis, high sensitivity and wide screening of patients in point of care applications.
In this context, spintronics devices offer a unique combination of features, making them very promising for the implementation of highly sensitive biosensors: magnetoresistive transducers, like giant magnetoresistance (GMR) or tunnelling magnetoresistance (TMR) sensors, are employed for the detection of the magnetic beads, which are used as labels of target molecules. The sensor, or its active area, has to be functionalized with the complementary molecular probe to immobilize the target molecules bound to the beads at its surface, thus giving an electrical signal via the magnetoresistive behaviour of the spintronic transducer.
The goal of the present project is to advance in the design and realization of microarrays of biosensors based on spintronic transducers,
pushing the limit of detection towards or beyond the actual values of standard bulky techniques based on fluorescence.
The research consortium of the present project is made up of three Units:
The final aim is developing a lab-on-chip system based on spintronic biosensors with biological sensitivity comparable or better than that of standard bulky systems like fluorescence.
The development of the lab-on-chip will be done with reference to a relevant clinical application which will be used for the comparative validation of the lab-on-chip system, i.e. the measurement of the level of mRNA prep1 in tumors for the identification of patients affected by lung cancer who do not need chemotherapy after a surgical removal.
The proposed project aims to enhance understanding and advance in the design and construction of
a new type of compact diagnostic tool for the analysis of biomarkers in biological samples, oriented to point of care medical applications and based on a lab on chip approach including microarrays of spintronic biosensors. As specific application for validation we will consider the identification of patients affected by lung cancer who do not need chemotherapy after a surgical removal of a tumor, via measurements of the level of Prep1 mRNA in biological samples taken during the surgical intervention.
Micrograph of a lung lymph node biopsy showing metastatic colorectal adenocarcinoma.
Our design will consist in a chip with 24 sensor points functionalized with specific oligonucleotides and coupled to a microfluidic apparatus for the delivery and transport of the liquids onto the sensor surface.
The realization of spintronic transducers and coatings for probe immobilization is based on the development of innovative materials: complex epitaxial heterostructures are the basic ingredients for the subsequent realization of spintronic devices, via micro and nanofabrication techniques for the lateral definition, and buffer polymeric layers with high density of binding sites uniformly distributed on their surface are necessary for the immobilization of biologic probes.
The following specific objectives will be pursued during the project: