RESUMO
Nanostructure-initiator mass spectrometry (NIMS) is an established method for sensitive detection of small molecules in complex samples. It is based on the optimal combination of a porous Si substrate and a carefully selected polymer coating to allow certain analytes of interest to be concentrated on the substrate for effective ionization with minimal background interference from conventional organic matrices. The previous chapter has detailed the history and current state of the art of the technique in small-molecule profiling and imaging applications. We describe here a simple step-by-step protocol for substrate fabrication and sample preparation that provides a starting point for the technique to be adapted and optimized for 2-D biological imaging applications.