Thermo‐Fluorescent Bactericidal Quantum Dots Based Smart Multifunctional Textiles via Molecular Surface Engineering and 3D‐Printed Interlocked Architectures

ABSTRACT Functional textiles integrating optical activity, environmental responsiveness, and structural adaptability are essential for next‐generation wearable systems. Here, we present a versatile strategy for fabricating thermo‐fluorescent, UV‐protective, and antibacterial smart textiles via carbon dot (CD)/polymer nanocomposite coatings. CDs synthesized hydrothermally exhibited strong excitation‐dependent emission (320–460 nm), a fluorescence lifetime of 4.2 ns, and excellent photostability over 30 days. The CDs formed hydrogen‐bonding interactions within a PVA/quaternized chitosan matrix and were deposited onto textiles using dip‐and‐dry and spray methods, followed by hexadecyltrimethoxysilane modification to impart durable hydrophobicity (water contact angle >100°). The coated fabrics maintained fluorescence under repeated mechanical deformation and showed coating‐cycle‐dependent emission. The functional cotton displayed thermo‐responsive fluorescence (5–100°C), with enhanced emission below 37°C and quenching above this temperature. The textiles showed strong antibacterial activity, with inhibition zones of ∼17 mm (E. coli) and ∼19 mm (B. subtilis). The textiles also demonstrated notable antioxidant performance (DPPH EC 50 = 88.6 µg mL − 1 ; ABTS EC 50 = 37.1 µg mL − 1 ) and excellent UV‐blocking, exceeding a 95% relative increment in UVB blocking at the highest coating level. Integration with digital light processing printing enabled mechanically interlocked hybrid architectures without compromising functionality, establishing a multifunctional platform for advanced smart textile applications.