MRI controlled magnetoelastic nano biosensor for in-vivo pH monitoring: A preliminary approach

Biosensors are a predominant research field and aim at providing small and novel methods for bio-recognition, bio-actuation and embedded data analysis to the medical and bioengineering domains. Typical biosensor technologies exploit optical, electrochemical or mechanical detection methods. Although many biosensors are designed to use biological samples for recognition and treatment, some are designed to be implantable on animals or human for direct detection. The presented work suggests the use of a magnetoelastic based biosensor for the wireless transmission of physiological data through the human body at capillary level. When excited by an external magnetic wave at a given frequency, the magnetoelastic core enters in a vibrating state and emits an alternative magnetic field in response. Using an external RF coils such as the one found in a magnetic resonance imaging (MRI) system, the magnetic flux generated by the magnetoelastic sensor core is received and analyzed during its transient response. Using a pH sensible functional polymer coated on the sensor core, physiological data fluctuations are translated into resonant frequency shifts which, in turn, are picked up by the coil. A preliminary approach for the sensor design and system architecture is presented.