  In the last few decades, the development of miniature biological sensors that
can detect and measure different phenomena at the nanoscale has led to
transformative disease diagnosis and treatment techniques. Among others,
biofunctional Raman nanoparticles have been utilized in vitro and in vivo for
multiplexed diagnosis and detection of different biological agents. However,
existing solutions require the use of bulky lasers to excite the nanoparticles
and similarly bulky and expensive spectrometers to measure the scattered Raman
signals, which limit the practicality and applications of this nano-biosensing
technique. In addition, due to the high path loss of the intra-body
environment, the received signals are usually very weak, which hampers the
accuracy of the measurements. In this paper, the concept of cooperative Raman
spectrum reconstruction for real-time in vivo nano-biosensing is presented for
the first time. The fundamental idea is to replace the single excitation and
measurement points (i.e., the laser and the spectrometer, respectively) by a
network of interconnected nano-devices that can simultaneously excite and
measure nano-biosensing particles. More specifically, in the proposed system a
large number of nanosensors jointly and distributively collect the Raman
response of nano-biofunctional nanoparticles (NBPs) traveling through the blood
vessels. This paper presents a detailed description of the sensing system and,
more importantly, proves its feasibility, by utilizing accurate models of
optical signal propagation in intra-body environment and low-complexity
estimation algorithms. The numerical results show that with a certain density
of NBPs, the reconstructed Raman spectrum can be recovered and utilized to
accurately extract the targeting intra-body information.
