Following hybridization on sensor/array platforms by using SPR,elipsometer and MALDI-MS

Abstract

The aim of this study is to develop a methodology in which Surface Plasmon Resonance (SPR), Ellipsometer (EM) and Matrix-Assisted Laser Desorption/Ionization-Mass Spectrometry (MALDI-MS) will be used together for detection of single-strand oligodeoxynucleotides (ssODNs) targets. A selected target-ssODNs, and its complementary, the probe-ssODNs carrying a -SH end group, a spacer arm (HS-(CH₂)₆–(T)₁₅, and a non-complementary ssODNs were used. Silicone based stamps with 16 regions were prepared and used for micro-contact printing (µCP) of the probe-ssODNs on the gold coated surfaces homogeneously. A modulator-spacer molecule (6-mercapto-1-hexanol) was co-immobilized to control surface probe density, to orientate the probe-ssODNs, and to eliminate the nonspecific interactions. SPR was used successfully to follow the hybridization of the target-ssODNs with the immobilized probe-ssODNs on the platform surfaces. Complete hybridizations were achieved in 100?min. It was obtained that there was a linear relationship between relative change in delta and target concentration below 1?µm. Using imaging version of ellipsometer (IEM) allowed imaging of the surfaces and supported extra datum for the SPR results. After a very simple dehybridization protocol, MALDI-MS analysis allowed detection of the target-ssODNs hybridized on the sensor/array platforms.