Nanomaterial based mass spectrometry of oligodeoxynucleotide–drug complexes

Abstract

Surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) using HgTe nanostructures as the matrix has been employed for the detection of four 15-base oligodeoxynucleotides (ODNs) that are genes found in acute myeloid leukemia (AML) patients and their complexes with mitoxantrone (MTX), which is a common drug for the treatment of AML patients. The major peaks for the four tested ODNs are at m/z values of 4571, 4586, 4610, and 4635, while they are at m/z values of 5017, 5031, 5055, and 5079 for their corresponding complexes with MTX. The ODN with a m/z value of 4610 is assigned to a normal gene of AML, while the other three are single-base mutant ODNs. This approach allows detection of the tested ODNs at concentrations down to 2 nM, showing their potential for the diagnosis of AML. The dissociation constant values of the four tested ODN–MTX complexes determined by the SALDI-MS approach are similar and at the μM level, which agree with that determined by applying a conventional absorption approach. Relative to the conventional approach, the SALDI-MS approach has advantages of simplicity, rapidity, reproducibility, and use of smaller amounts of ODNs and MTX.