Lifetime chemical sensor arrays of organic fluorophores for bacterial fingerprinting.

The rise of multi-drug resistant bacteria constitutes a global challenge with direct impact on millions of patients worldwide. The identification of bacterial species is essential to avoid unnecessary use of antibiotics and to minimize the emergence of additional resistance; however, there are few chemical strategies to identify resistant species in a rapid and unbiased manner. Cross-reactive arrays combine multiple sensor components to produce distinctive fingerprints for similar targets; herein, we present a cross-reactive sensing array built with long lifetime organic fluorophores. To the best of our knowledge, we synthesize the largest collection to date of bioconjugatable triangulenium fluorophores by including heteroatom and side-chain diversification for spectral and lifetime diversity, as well as water-soluble and orthogonal moieties for peptide tagging and compatibility with biological samples. After optimization, we evolve a four-fluorophore sensor array that correctly assigns all seven ESKAPEE bacterial species by combining their optical signatures. Lifetime chemical sensor arrays will open avenues for concentration-independent, reliable and sensitive optical detection without the need for prior knowledge of molecular targets.