Surface plasmon coupled emission enabled silver-C60 nano-biosensors for sensitive detection of tuberculosis

摘要

OpinionThe current global scenario for diagnosing the fatal tuberculosis (TB) disease includes techniques like chest X-ray that show cavitary lesions indicating the presence of an active TB infection. This is often further substantiated with a confirmatory diagnosis involving the fluorescence microscopy aided positive identification of the causative organism; Mycobacterium tuberculosis (Mtb) in the blood or sputum of patients. However, expensive infrastructure in the form of X-ray and cell-culture/fluorescence microscopy facilities may not be present in resource limited settings (RLS) of the under-developed and developing nations where TB is highly prevalent. Furthermore; the standard microscopy based detection of TB bacteria involving fluorescence is limited by the isotropic nature of the fluorescence phenomenon itself, which is innately associated with poor signal collection efficiency and low signal-to-noise ratios. These limitations that hinder the early and positive identification of the TB disease condition may result in even the death of the patient. Therefore, in addressing this crucial need for developing efficient sensing strategies; we present the novel Surface Plasmon Coupled Emission (SPCE) sensing platform that enables the generation of highly amplified fluorescence signals with excellent signal collection efficiency, from low sample volumes; as a promising tool for enabling the highly sensitive and rapid diagnosis of tuberculosis. In this regard, we have employed Ag-C60 thin-film substrates, which we have previously reported as low-cost and highly sensitive fluorescence sensor platforms, along with the well-established acid-fast fluorescence staining protocol that offers specificity to detection of Mtb. This synergistic approach allowed us to perform the early, sensitive and specific diagnosis of TB in an economically viable manner. Introduction Tuberculosis or TB ( tubercle bacillus ), which is also known as phthisis, phthisis pulmonalis, or consumption; is a widespread and highly infectious disease that is usually caused by Mycobacterium tuberculosis , which is a pathogenic bacteria belonging to the mycobacterium genus ~(1). Tuberculosis typically attacks the?lungs, but can also affect other parts of the body. Tuberculosis is considered to be highly infectious in nature.?Most infections do not show any symptoms (asymptomatic) and are hence known as?cases of latent tuberculosis. From statistical analysis it has been determined that, about one in ten latent infections eventually progresses to the active disease state, which if left untreated, kills more than 50% of those infected.