Surface-based biosensors have proven to be of particular interest in the monitoring of human pathogens by means of their distinct nucleic acid sequences. Genosensors rely on targeted gene/DNA probe hybridization at the surface of a physical transducer and have been exploited for their high specificity and physicochemical stability. Unfortunately, these sensing materials still face limitations impeding their use in current diagnostic techniques. Most of their shortcomings arise from their suboptimal surface properties, including low hybridization density, inadequate probe orientation, and biofouling. Herein, we describe and compare two functionalization methodologies to immobilize DNA probes on a glass substrate via a thermoresponsive polymer in order to produce genosensors with improved properties. The first methodology relies on the use of a silanization step, followed by PET-RAFT of NIPAM monomers on the coated surface, while the second relies on vinyl sulfone modifications of the substrate, to which the pre-synthetized PNIPAM was grafted to. The functionalized substrates were fully characterized by means of X-ray photoelectron spectroscopy for their surface atomic content, fluorescence assay for their DNA hybridization density, and water contact angle measurements for their thermoresponsive behavior. The antifouling properties were evaluated by fluorescence microscopy. Both immobilization methodologies hold the potential to be applied to the engineering of DNA biosensors with a variety of polymers and other metal oxide surfaces.

Herein, we report a post-synthetic modification strategy to covalently graft polyamines, including ethylenediamine (ED), diethylenetriamine (DETA), tris(2-aminoethyl)amine (TAEA), and polyethyleneimine (PEI) to the amino-ligand of a Cr-MOF, NH2-Cr-BDC, for post-combustion carbon capture applications. X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) reveal that ~45% of the MOF ligands are grafted with polyamines. Also, after assessment of CO2 uptake, CO2/N2 selectivity, isosteric heats of CO2 adsorption, separation performance during humid CO2/N2 (15/85) breakthrough experiments, and cyclability, the study reveals an enhanced performance for the polyamine composites and the following performance trend: NH2-Cr-BDC<ED<DETA<TAEA<PEI. The best-performing materials, including TAEA and PEI-grafted MOFs, offer CO2 uptakes of 1.0 and 1.55 mmol/g, respectively, at 0.15 bar and 313 K. Further, these composites also offer a high CO2 capacity after 200 temperature swing adsorption/desorption (TSA) cycles in simulated humid flue gas. Last, after soaking the composites in water, we show that there is no loss of CO2 capacity; on the contrary, when the same MOF is impregnated with polyamines using traditional approaches, there is ~85 % CO2 capacity loss after soaking. Thus, this covalent grafting strategy successfully immobilizes amines in MOF pores preventing leaching and hence could be an effective strategy to extend adsorbent lifetime.

Atom-thin porous graphene membranes offer unprecedented carbon capture performance thanks to Å-scale pores that combine ultrahigh permeance with attractive selectivity. However, incorporating a high pore density has until now required high-temperature ozone oxidation, while oxidation at room temperature was found to be sluggish, limiting scalability. Herein, we uncover that graphene oxidation by ozone is constrained by mass transfer of ozone and concentration polarization from the accumulation of reaction byproduct at the surface. We overcome this bottleneck using micro channeled flow reactor that enhances mass transfer, accelerating the oxidation rate, leading to a tenfold higher pore density at room temperature. The process yields centimeter-scale membranes containing a high density of CO₂-selective pores that achieve attractive CO₂/N₂ separation performance. A brief subsequent room temperature pore expansion step further boosts performance. Our fully ambient, scalable protocol eliminates high-temperature equipment, paving a scalable route to industrial production of high-performance porous graphene membranes for carbon capture.