Engineering Isolated Molecules to Optoelectronic Nanohybrids: One- and Two-Photon Excited Aggregation-Induced Enhanced Emission in (Z)-2-([1,1′-Biphenyl]-4-yl)-3-(4-(3-aminopropoxy)phenyl)acrylonitrile and Laponite Nanoclay

We report the design, fabrication, and greatly enhanced aggregation-induced emission (AIE) produced by both one-photon and two-photon excitation of a (Z)-2-([1,1′-biphenyl]-4-yl)-3-(4-(3-aminopropoxy)phenyl)acrylonitrile (BPCSA)–laponite hybrid system. Pristine BPCSA in DMSO exhibited weak fluorescence, while in water (f_w = 99%), it formed luminescent aggregates with intense blue emission, confirming its AIE behavior. Optical and scanning electron microscopy studies further revealed a progressive transition from a molecular dispersion in DMSO to compact aggregates in water, correlating with enhanced emission. We demonstrate that the incorporation of BPCSA dye onto laponite platelets produces a significant enhancement in emission intensity compared to a dispersion in water, which we attribute to electrostatic interactions between the dye and clay galleries that restrict intramolecular motion, thereby reducing nonradiative decay. Both linear and nonlinear fluorescence measurements consistently demonstrate enhanced emission intensity at lower concentrations (10 μM) relative to higher ones. Fluorescence lifetime measurements of BPCSA showed a significant increase from 0.11 to 1.33 ns in the laponite hybrid, with the quantum yield increasing dramatically from 6.4% to 66.6% when incorporated into a 0.5 wt % aqueous dispersion of laponite, evidencing reduced nonradiative decay. The donor−π–acceptor molecular framework of BPCSA, coupled with clay-induced rigidity, amplifies both linear and nonlinear optical responses. These findings establish the BPCSA–laponite hybrid as a promising candidate for sensors, fluorescent probes, and optoelectronics applications requiring strong emissive properties.