MIL-101(Cr) MOF Nanoparticles and MALDI-TOF Mass Spectrometry for the Detection of <i>Mycobacterium tuberculosis</i> Biomarkers

This study presents Materials Institute Lavoisier (MIL)-101(Cr) metal–organic framework (MOF) nanoparticles used for the detection of 6-kDa early secreted antigenic target (ESAT-6) and 10-kDa culture filtrate protein (CFP-10) biomarkers from the Mycobacterium tuberculosis complex (MTBC). The presence of CFP-10 and its fragment D7-F100 CFP-10, ESAT-6, and its variant ESAT-6*, along with their doubly charged peaks below 6 kDa, were detected using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with MIL-101(Cr) MOF nanoparticles. The mass peaks (mass-to-charge ratio, m/z) observed at approximately 10100 and 10660 correspond to CFP-10, while those at 7931, 7974, 9750, and 9796 correspond to ESAT-6. The adsorption of tuberculosis (TB) biomarkers by MIL-101(Cr) nanoparticles was primarily driven by electrostatic interaction, hydrogen bonding, and functional group binding, enabling selective protein enrichment. Their high surface area and pore volume provide accessible adsorption sites for TB-specific proteins. The sensitivity and specificity of MTBC samples reached 94.3 and 100%, respectively, and no TB biomarkers were detected in nontuberculous Mycobacteria (NTM) samples, indicating that these biomarkers effectively distinguish MTBC from NTM. This study featured a qualitative analysis MOF-based MALDI-TOF MS platform, which developed a robust and scalable alternative to the diamond nanoparticle platform. Overall, MALDI-TOF MS combined with MIL-101(Cr) nanoparticles offers a promising approach for improving TB biomarker detection, leading to more efficient and reliable strategies for TB detection.