Ultrathin Layer-by-Layer Hydrogels with Incorporated Gold Nanorods as pH-Sensitive Optical Materials

Abstract

We report ultrathin pH-responsive plasmonic membranes of [poly(methacrylic acid)-gold nanorods] 20 (PMAA-Au NRs) 20 with gold nanorods embedded into swollen cross-linked LbL hydrogels. In contrast to the most of known pH responsive materials which rely on pH-triggered change in the intensity of photoluminescence or plasmon bands, the responsive structures suggested here exhibit a significant pHtriggered shift in easily detectable, strong plasmon resonance band. We show that a pH-induced deswelling of the (PMAA-Au NRs) 20 hydrogel film in the pH change from 8 to 5 causes a dramatic blue-shift of the longitudinal plasmon peak by 21 nm due to the increased side-by-side interactions of adjacent gold nanorods. These composite hydrogel multilayer films can be released from the substrates yielding freefloating and optically pH-responsive ultrathin hydrogel films which can be transferred to the appropriate solid substrates.

Semiconductor Anisotropic Nanocomposites Obtained by Directly Coupling Conjugated Polymers with Quantum Rods

“…P3HT possesses excellent solution processability, environmental stability, high charge-carrier mobility, and tailorable electrochemical properties. [2] Owing to their quantum-confined nature, for quantum dots (QDs) such as cadmium selenide (CdSe), [3] variation of the nanocrystal size provides continuous and predictable changes in fluorescence emission, [4,5] thus rendering them useful for a wide range of applications in photovoltaic cells, [6,7] LEDs, [8] biosensors, [9] and bio-imaging. [9] CP-based organic/inorganic hybrid solar cells (e.g., CP/QD composites) are favorable alternatives to inorganic solar cells as they have many advantages peculiar to CPs, such as light weight, flexibility, processability, roll-to-roll production, low cost, and large area.…”

Nanoplasmonic sensing for nanomaterials science

“…They also showed that the swelling behavior of the brush was not affected by the presence of the nanoparticles. Similarly Kozlovskaya et al used nanorods incorporated into thin (55 nm) layer-by-layer hydrogels to detect pH changes [49] .…”

pH-responsive PMAA-b-PEG-b-PMAA triblock copolymer micelles for prednisone drug release and release kinetics

“…Specifically, poly(N-isopropylacrylamide) (PNIPAAm) and poly(methylacrylic acid) (PMAA) have been focused on thermo-and pH-sensitive behavior [4][5][6]. Since pHsensitive carriers can target drugs to deep organs or tumor tissues, PMAA-based amphiphilic block copolymer micelles have widely been investigated for these applications.…”