Fabrication of titanium based MALDI bacterial chips for rapid, sensitive and direct analysis of pathogenic bacteria

For the first time, we report the fabrication of a titanium bacterial chip for MALDI-MS produced from a simple, cost effective and rapid heat treatment process. This bacterial chip can be reused many times and is highly versatile. These bacterial chips serve dual roles: (1) They can be applied as MALDI-MS target plates for direct and highly sensitive bacterial analysis. (2) They can be used as bacterial sensors for direct analysis of the captured bacteria using MALDI-MS. The sensitivity of these chips when used as bacterial sensors is <103 cfu/mL. The lowest detectable concentration for direct MALDI-MS analysis was found to be 104 cfu/mL. The results were further justified by using standard plate counting method combined with Tukey–Kramer statistical analysis and fluorescence imaging followed by image processing for fluorescence quantification using ImageJ software to substantiate the MALDI-MS results.

► For first time report fabrication of titanium biochip for MALDI-MS. ► Produced from simple, cost effective rapid heat treatment process. ► Biochips serve dual purposes. MALDI-MS target plates for direct bacteria analysis. ► Biosensors for direct analysis of the captured bacteria using MALDI-MS. ► Sensitivity of these chips as biosensors is <103 cfu/mL.