Optimized derivatization of primary amines with the fluorogenic reagent naphthalene-2,3-dicarboxaldehyde toward reproducible quantitative analysis in biological systems.

Primary amines are the target of many bioanalytical analyses, as they are ubiquitous in biological systems and responsible for numerous important processes including neurotransmission and cell signaling. Primary amines can be sensitively detected via fluorescence after their reaction with the fluorogenic reagent naphthalene-2,3-dicarboxaldehyde (NDA) in the presence of cyanide through the formation of fluorescent N-substituted 1-cyanobenz[f]isoindole (CBI) derivatives. While fluorogenic reagents such as NDA can be advantageous for sensitive detection, improvements in both long-term stability and speed of reaction are necessary to enable practical and reproducible quantitative analysis.