Programming Energy–Bio Interfaces through Ligand-Directed Electronic Transport in Atomically Precise Gold Nanoclusters

<title>Abstract</title> <p> Engineering multifunctional nano-systems with programmable electronic transport remains a fundamental challenge for integrating optical, catalytic, and biomedical functions within a single nanomaterial. Herein, a new aromatic-amide functionalized chiral small ligand, (R)-5-(1,2-dithiolan-3-yl)-N-(napthalen-1-yl)-pentanamide (NDLA), has been synthesized to construct atomically precise gold nanoclusters (NDLA-AuNCs) with tailored electronic and interfacial properties. The resulting NDLA-AuNCs exhibit near-infrared emission (800–1200 nm), pronounced exciton-coupled circular dichroism, and intrinsic semiconducting behaviour governed by a correlated barrier hopping mechanism, with a Mott temperature of 1.4 × 10 ⁶ K, localization length of 0.3 nm, and density of states at fermi level of 4.9 × 10 ²¹ states· eV ^− 1 _· cm ^− 3 , demonstrating ligand-directed chirality transfer and charge migration through localized electronic states. The resulting electronic architecture promotes rapid interfacial charge transfer that drives superior electrocatalytic hydrogen evolution compared with reported bare AuNCs. In a biological environment, the same charge-transport dynamics drive ROS generation under dark and light, inducing mitochondrial dysfunction and potent triple-negative breast cancer cytotoxicity, while preserving excellent in vitro and in vivo biocompatibility. By directly correlating ligand chemistry with electronic transport, this work establishes electronic structure engineering as a proof-of-concept for programming multifunctionality in nanoscale materials and provides an integrated “energy-bio interface” framework for designing next-generation catalytic and therapeutic nano-systems. </p>