Bio-security for health monitoring and diagnosis are the needs of the hour, for rapid detection of biological and chemical species. This calls for a necessity to develop a cost effective miniaturized and portable biosensor device for in-situ biomedical applications and Point-of-Care Testing (POCT). While portability of the biosensor is required for in-situ medical detections, miniaturization is essential for handling smaller sample volumes and high throughput. Thus, the above mentioned concerns cannot be addressed unless a fully integrated biosensor system is developed. In this work, an integrated opto microfluldic based Lab-on-a-chip device is proposed for carrying out fluorescence based biodetection. The input and output fibers were integrated with the microfluidic channel so as to make a robust setup. Fluorescence detection was carried out using Alexafluor 647 tagged antibody particles and the output was measured with a Spectrometer-on-Chip, integrated with the device. The experimental results prove that the proposed device is highly suitable for Lab-on-a-Chip applications.