Detection of Mycobacterium tuberculosis complex and Mycobacterium gordonae on the same portable surface plasmon resonance sensor

In the present study, we have developed a specific detection system for Mycobacterium tuberculosis complex (MTB complex) and Mycobacterium gordonae by using a commercially available SPR based portable-multichannel sensor system. The probe single-strand oligodeoxynucleotides (probe-ssODNs), which also contain suitable spacer arms, against the target characteristic sequence (target-ssODNs) of both species were selected and synthesized. The SPR sensors were prepared by direct coupling of thiolated probes on gold-coated sensor surfaces. 6-Mercapto-1-hexanol was used as orientation helper and surface blocking agent. Immobilization protocol was optimized. The validation test results showed that the detection limit of sensor platform has been found to be 30 ng mu l(-1). Developed sensor can be used to detect specific DNA hybridization at a concentration of 0.05 mu M. The sensor chip surface can be regenerated with exposure to 2.5 mM HCl quite effectively and reused several times without losing the signal intensity. The SPR sensors carrying the probe-ssODNs were kept in vacuum at room temperature in the dark for about 12 weeks, and used effectively. (c) 2010 Elsevier B.V. All rights reserved.