An IMPLICATION-logic-based fluorescent probe for sequential detection of Cu2+ and phosphates in living cells

Abstract

Cu²⁺ and inorganic phosphates play an extremely important role in organisms and the environment. However, designing probes for the simultaneous identification and detection of Cu²⁺ and phosphates to construct a multi-input optical logic system remains a challenge. Herein, a novel IMPLICATION logic fluorescent sensor (HL) based on a triphenylamine derivative has been designed and synthesized, and sequentially demonstrated high selectivity for Cu²⁺ and inorganic phosphates, which serve as energy modulators/inputs over a wide pH range. The chemosensor HL first formed a 2 : 1 complexation ratio with Cu²⁺ with a low detection limit of 0.17 μM, and the prepared HL–Cu complex was then used for the detection of phosphates and showed good selectivity over common anions. Furthermore, the probe exhibited excellent cell biotoxicity and intracellular biosensing ability with an “on–off–on” fluorescence response as the optical signal reporter/output for the IMPLICATION logic behavior under the two chemical inputs of Cu²⁺ and phosphate groups.