Zarif Ahmad Razin Bhuiyan

Enantioselective chiroptical sensing is gaining traction across various applications. However, intrinsic molecular chiroptical responses are weak, and existing amplification approaches add synthesis, manufacturing, or operational complexity that limits sensitivity and scalability. Here, we present an enantioselective sensing paradigm merging adsorption-driven chirality induction with large-scale optical transduction in twisted stacks of aligned carbon nanotube (CNT) films. Chiral molecules adsorb onto CNTs to form chiroptically active composites that are macroscopically assembled by alignment and rotational stacking, yielding large ultraviolet circular dichroism (CD). We resolve enantiomer handedness and quantify concentration in single-enantiomer aqueous solutions using a single sensor without lithography, hotspot delivery, or a paired opposite-handed reference. We achieve high sensitivity with estimated sub-μM minimum detectable concentrations for glucose and provide a proof-of-concept demonstration with alanine. Neither analyte-only solution shows detectable CD under the present measurement conditions. We demonstrate Langmuir-type adsorption behavior using molecular dynamics simulations and reproduce experimental results using optical simulations. This platform provides a foundation for future development toward cost-effective in situ enantiomer monitoring in aqueous environments.

Materials with exceptionally low thermal conductivity are desirable for thermal insulation and waste heat recovery. While foams and aerogels boast ultralow thermal conductivities akin to air, lack of mechanical stiffness in these soft materials necessitates a paradigm shift in materials design that can offer thermal insulation and mechanical rigidity simultaneously. Here, we show that spun-cast layered hybrid organic-inorganic perovskite thin films, azobenzene ethyl ammonium lead iodides, exhibit a record-low thermal conductivity, down to ∼0.04 watts per meter per kelvin at room temperature, while maintaining mechanical rigidity with an elastic modulus of 7.7 gigapascals that surpasses that of most plastics, foams, and aerogels. This unusual combination of ultralow thermal conductivity and high mechanical rigidity is attributed to the specially engineered organic cations in the layered structure. Our finding highlights the potential of molecular engineering in hybrid layered structures to push the extreme of thermal insulation in dense, rigid solids.

Achieving low thermal conductivity in nonporous polymer materials without compromising mechanical integrity remains a longstanding challenge. Conventional strategies, such as introducing porosity, are inherently limited in dense systems. Here, we demonstrate that thermal transport in polymer–organic filler hybrids is closely associated with the engineered availability of thermally accessible vibrational modes, rather than individual interfacial resistance or porosity. Using PU/organic filler hybrids as a model system, we show that incorporating rigid organic motifs shifts the vibrational density of states toward higher frequencies, where vibrational modes are weakly thermally populated at ambient conditions. This limits the number of heat-carrying channels, leading to suppressed thermal conductivity despite negligible individual interfacial resistance (~10⁻⁹ m² K W⁻¹). These findings provide initial evidence that vibrational mode engineering may offer a promising molecular-level route for reducing thermal conductivity in dense polymer-organic hybrid systems.