Single-molecule multi-target fluorescent imaging for latent fingerprints based on aggregation-induced emission

Existing latent fingerprint developers achieve marvelous progress during the past decades. However, most of these methods mainly consider single target substance, which may face difficulties in latent fingerprint imaging when the corresponding substance is absent from latent fingerprint traces. To alleviate this issue, we propose a novel single-molecule multi-target green fluorescent probe, TPE-NI-NHS, which could target both lipids and amino acids through physical adsorption and chemically bonding under mild conditions, respectively. Specifically, tetraphenylethylene and active ester group in TPE-NI-NHS are connected at two ends of the naphthalimide core, which provide perfect aggregation-induced emission, accurate and quick reaction with amino acids, lipophilic properties, and green fluorescence emission. As expected, TPE-NI-NHS achieves green fluorescent imaging for latent fingerprints contained different contents of lipids and amino acids with high quality, high sensitivity, and high contrast under mild conditions. In summary, TPE-NI-NHS developer provides multiple targeting features, novel imaging principles and mild imaging process to latent fingerprint detections.