A water-stable protected isocyanate glass array substrate.

We describe the performance of a new glass attachment chemistry for arrays that is particularly well suited to attachment of small molecules, such as peptides. The attachment chemistry is a protected isocyanate (PI) group. Isocyanate groups are well suited to serving as a glass coating for arrays, in that they are highly reactive with many different types of biological compounds. However, they are generally so reactive as to be unstable. The new feature of the PI slide coating is its stability. It can withstand immersion in water without loss of reactivity and has at least a 1-year shelf life. The high reactivity of the PI group results in a rapid coupling reaction (< 15min) and is particularly useful for attaching small molecules, such as peptides. Since isocyanates bind to both amines (forming a urea linkage) and hydroxyl groups (forming a carbamate bond), we tested the ability of the PI coating to bind to a wide variety of compounds. We found that the PI slide coating can directly attach to peptides, proteins, carbohydrates, lipooligosaccharides, and DNA. The sensitivity of detection for these compounds is comparable to that of other previously published array substrates.