Optoelectronic effects differentiating absorption of right and left circularly polarized photons in thin films of chiral materials are typically prohibitively small for their direct photocurrent observation. Chiral metasurfaces increase the electronic sensitivity to circular polarization, but their out-of-plane architecture entails manufacturing and performance trade-offs. Here, we show that nanoporous thin films of chiral nanoparticles enable high sensitivity to circular polarization due to light-induced polarization-dependent ion accumulation at nanoparticle interfaces. Self-assembled multilayers of gold nanoparticles modified with l-phenylalanine generate a photocurrent under right-handed circularly polarized light as high as 2.41 times higher than under left-handed circularly polarized light. The strong plasmonic coupling between the multiple nanoparticles producing planar chiroplasmonic modes facilitates the ejection of electrons, whose entrapment at the membrane-electrolyte interface is promoted by a thick layer of enantiopure phenylalanine. Demonstrated detection of light ellipticity with equal sensitivity at all incident angles mimics phenomenological aspects of polarization vision in marine animals. The simplicity of self-assembly and sensitivity of polarization detection found in optoionic membranes opens the door to a family of miniaturized fluidic devices for chiral photonics.

Herein, the design of a DNA-based chiral biosensor is described utilizing the self-assembly of shell core-gold (Au) satellite nanostructures for the detection of mycotoxin, ochratoxin A (OTA). The assembly of core-satellite nanostructures based on OTA-aptamer binding exhibits a strong chiral signal with an intense circular dichroism (CD) peak. The integrity of the assembly of core-satellite nanostructures is limited to some extent in the presence of different levels of OTA. Correspondingly, the chiral intensity of assembly is weakened with increasing OTA concentrations, allowing quantitative determination of the target. The developed chiral sensor shows an excellent linear relationship between the CD signal and concentrations of OTA in the range of 0.1-5 pg mL with a limit of detection as low as 0.037 pg mL . The effectiveness of the biosensor in a sample of red wine is verified and a good recovery rate is obtained. These results suggest that the strategy has great potential for practical application.

Detection of cancer markers is important for early diagnosis and timely treatment of cancer. In this study, we fabricated a tailorable gold nanofilm-anodized aluminum oxide (Au-AAO) ion channel through nanoparticle self-assembly and proposed a highly sensitive and selective Mucin 1 (MUC1) detection method. By engineering the optimal layers of the Au-AAO ion channel and encoding the aptamer between the interlayers, a highly controllable ion rectification phenomenon was observed. From this, the relationship between the rectification ratio (RR) and the concentration of MUC1 was established and the highly sensitive detection of MUC1 is achieved. We found that the aptamer-modified Au-AAO ion channel has a good linear range within the MUC1 concentration of 1–104 fg mL–1 and the limit of detection (LOD) was as low as 0.0364 fg mL–1 (0.0025 aM). Thus, this research opens a new horizon for fabricating multi-functional ion channels as well as developing ultrasensitive detection technologies.

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Chiroptical nanomaterials have generated significant levels of interest for generating strong circularly polarized luminescence (CPL) signals. We used the Langmuir–Schaeffer technique to generate the continuous and compact assembly of CdSe/CdS chiral film. We assembled achiral CdSe/CdS nanorods by controlling the number of layers and angles between different layers. This allowed us to tailor chiroptical properties to achieve high CPL signals. The chiral film was symmetrical and had the highest circular dichroism (CD) response and CPL signals with ten layers (RH (right‐handed)‐/LH (left‐handed)‐5 + 5 layers) and a 45° inter‐angle. Specifically, RH‐5+5 of the chiral film exhibited 1431 mdeg of CD activity and strong CPL signals with a dissymmetry factor (glum) of 0.0997. The helical stacked crystal plates with linear birefringence resulted in strong circular birefringence, as determined by the Reusch model. Electromagnetic simulations indicated that such remarkable optical activity was attributed to the birefringence and dichroism of the well‐aligned CdSe/CdS nanorod layers in the chiral films. Under right/left circular polarized (RCP/LCP) light excitation, the well aligned semiconductor nanorods exhibited differences in the coupling efficiencies to RCP and LCP light. Our CdSe/CdS chiral films, which exhibit ultra‐strong CPL activity, will provide a novel strategy for the fabrication of chiroptical devices.

Methacrolein oxide (MACRO) is an important carbonyl oxide produced in ozonolysis of isoprene, the most abundantly-emitted non-methane hydrocarbon in the atmosphere. We employed a step-scan Fourier-transform infrared spectrometer to investigate the source reaction of MACRO in laboratories. Upon UV irradiation of precursor CH2IC(CH3)CHI (1), the CH2C(CH3)CHI radical (2) was detected, confirming the fission of the allylic C‒I bond rather than the vinylic C‒I bond. Upon UV irradiation of (1) and O2 near 21 Torr, anti-trans-MACRO (3a) was observed to have an intense OO-stretching band near 917 cm−1, much greater than those of syn-CH3CHOO and (CH3)2COO, supporting a stronger O‒O bond in MACRO because of resonance stabilization. At increased pressure (86‒346 Torr), both reaction adducts CH2C(CH3)CHIOO (4) and (CHI)C(CH3)CH2OO (5) radicals were observed, indicating that O2 can add to either carbon of the delocalized propenyl radical moiety of (2). The yield of MACRO is significantly smaller than other carbonyl oxides.

We constructed at ailorable membrane channel system consisting of penicillamine molecules intercalated in copper selenide nanoparticles (Cu 2Àx Se NPs), which exhibited circular dichroism (CD) bands in the near infrared region (CD,8 00-1600 nm) with am aximum intensity of 164.5 mdeg at 1440 nm. The chiral ligand hybridized to the surface of achiral Cu 2Àx Se NPs by breaking the intrinsic symmetry of Cu 2Àx Se NPs and further large-scale assembly induced strong optical activity.T he fabricated multilayer chiral membrane achieved an increased rectification ratio (RR) up to 114. The integration of penicillamine allowed for high enantioselective recognition against naproxen,which displayed high sensitivity with alimit of detection (LOD) as low as 0.027 nM.

The deposition of a monolayer nanoarray on the surface of a micrometer‐thick substrate is demonstrated, producing rectification characteristics at the nanoscale. The experimental results show that the heterogeneity of the structure and the charge density are the two key factors affecting rectification, which was confirmed with molecular dynamic (MD) and finite element simulations. Moreover, by altering the asymmetric electrolyte environment, the fabricated heterogeneous membrane can be used in energy conversion. This study provides insights into the mechanism underlying the generation of rectification and related factors, providing a theoretical basis for the characteristics of rectification.