Dual-Approach Electrochemical Surface-Enhanced Raman Scattering Detection of Mycobacterium tuberculosis in Patient-Derived Biological Specimens: Proof of Concept for a Generalizable Method to Detect and Identify Bacterial Pathogens

Abstract

The recent surge in infectious disease-causing pathogens, resulting in global catastrophe, has merited a pivotal quest toward point-of-care (POC) diagnostics. Mycobacterium tuberculosis (MTB) is still the top bacterium-based infectious disease-causing pathogen worldwide. In a concerted effort toward simplifying and decentralizing the discriminatory screening of MTB causing pathogens, electrochemical surface-enhanced Raman scattering (EC-SERS) was adopted to create a customized screening tool. The development strategy combined five key factors, including (i) a simplified Tollens'-based chemical synthesis method for bulk supply of silver nanoparticles, (ii) the deliberate surface modification of nanoparticles with carefully selected polyelectrolytes to resemble the conditioning layer usually found on a natural substratum, (iii) uniform SERSactive films formed through simple unprogrammed assembly, (iv) the controlled manipulation of the local electric field through applied voltage using a technique that does not conform to the limitations of classical EC-SERS, and (v) the inherent specificity of the target-specific SERS vibrational signature. The EC-SERS platform was able to discriminatively detect and identify TB-derived mycobacteria, including three clinically relevant MTB strains, TB-H37Rv, TB-HN878, and TB-CDC1551. Moreover, a customized voltage stepping protocol, compatible with either the inclusion of a short preincubation step or with in situ EC-SERS is illustrated. From the obtained SERS vibrational signatures, a band indicating a mode unique to TB-derived/TB-affiliated mycobacteria and thus not observed for other bacterial types used in this study was illustrated. Furthermore, provisional investigation, done as prelude for assessing the potential for translational adaptability of the EC-SERS technique toward POC clinical settings for sputum and urine specimens, was carried out.

Rapid and highly sensitive detection of bacterial pathogens using AgSnO/Si chip

“…The Raman spectra of all samples display a weak peak at approximately 520 cm − 1 , corresponding to the Si substrate. The peaks around 500, 592, 611, 667, 740, 773, 861, 885, and 948 cm − 1 represent the different vibrational modes of MB [23][24][25][26][27][28][29]. The peak around 1620 cm − 1 , corresponding to stretching c-c ring, is the signature Raman peak of MB [30].…”

Rapid Mycobacterium abscessus antimicrobial susceptibility testing based on antibiotic treatment response mapping via Raman Microspectroscopy

“…Furthermore, the current CAST-R cost per sample for susceptibility testing for two drugs at four different concentrations is approximately $8 (The cost of the required D 2 O is $2, Raman testing is $5, and other experimental materials is $1), a substantially lower cost than that of conventional AST conducted using the broth dilution method ($15 for mycobacterial susceptibility testing of two drugs). Specially, it has been widely reported for the detection of Mycobacterium tuberculosis via Raman Microspectroscopy [ 28 – 30 ]. Thus, the CAST-R may also apply to Mycobacterium tuberculosis which brings greater economic benefits and time savings.…”

Recent advances in antibiotic resistance diagnosis using SERS: focus on the “Big 5” challenges

“…In another application, electrochemical-SERS (EC-SERS) approach has been successfully applied for the detection of TB . 129 For example, Karaballi et al reported an EC-SERS DNA aptasensor platform for the label-free SERS detection of TB DNA biomarker in urine. 130 They used a cost-effective carbon screen printed electrode modified with AgNPs.…”