# Cooperative Raman Spectroscopy for Real-time In Vivo Nano-biosensing

## TL;DR

This paper introduces a cooperative nano-device network for real-time in vivo Raman spectroscopy, replacing bulky equipment with distributed nanosensors to improve accuracy and practicality in nano-biosensing.

## Contribution

It proposes a novel cooperative Raman spectrum reconstruction system using interconnected nanosensors for in vivo applications, demonstrating feasibility with models and algorithms.

## Key findings

- Reconstructed Raman spectra enable accurate intra-body information extraction.
- Distributed nanosensors can replace bulky Raman spectroscopy equipment.
- Numerical results confirm the system's effectiveness with sufficient NBP density.

## Abstract

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.