Low cost submicron patterning technique to fabricate a large area polymeric replica mold using an ultraviolet nanoimprint lithography (UV-NIL) technique is reported. A photo-curable polyurethaneacrylate (PUA) precursor was densified via UV light in order to form a solid polymeric replica mold and to maximise its stability, yet stable mechanical properties with different UV-exposure times were studied using a nanoindentation method as a function of the penetration depth during the loadingunloading cycles. The PUA replica mold demonstrated very high mechanical properties of hardness (0.15 GPa) and elastic modulus (2.7 GPa) due to the increased cross-linking density of the PUA precursor at an optimized UV-exposure time of 600 s. The PUA replica mold demonstrated potential for the fabrication of multi-scale line-and-space patterns with sizes of 350 nm or less with good uniformity and reproducibility over large areas. The replication of the polymeric mold with high durability and excellent mechanical properties can be economically valuable to physical contact nanolithography processes for the high throughput fabrication of micro-and nanodevices.

A versatile and efficient asymmetric synthesis of 2-monoand 2,3-trans-disubstituted azetidines with excellent diastereomeric (de = 93 to Ն 96%) and enantiomeric excesses (ee Ն 96%) in good overall yields is described. Virtually stereoisomerically pure differently N,O-protected 3-amino-1-alkanols were prepared as intermediates. Key steps are a diastereoselective α-alkylation of aldehyde SAMP-hydrazones with benzyloxymethyl chloride as the electrophile, and a nucleophilic 1,2-addition of various organocerium reagents to

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This report presents biotin-functionalized semiconducting polymers that are based on fluorene and bithiophene co-polymers (F8T2). Also presented is the application of these polymers to an organic thin film transistor used as a biosensor. The side chains of fluorene were partially biotinylated after the esterification of the biotin with corresponding alcohol-groups at the side chain in F8T2. Their properties as an organic semiconductor were tested using an organic thin film transistor (OTFT) and were found to show typical p-type semiconductor curves. The functionality of this biosensor in the sensing of biologically active molecules such as avidin in comparison with bovine serum albumin (BSA) was established through a selective decrease in the conductivity of the transistor, as measured with a device that was developed by the authors. Changes to the optical properties of this polymer were also measured through the change in the color of the UV-fluorescence before and after a reaction with avidin or BSA.

Solution‐processable organic semiconductors have been investigated not only for flexible and large‐area electronics but also in the field of biotechnology. In this paper, we report the design and fabrication of biosensors based on completely organic thin‐film transistors (OTFTs). The active material of the OTFTs is poly(9,9‐dioctylfluorene‐co‐bithiophene) (F8T2) polymer functionalized with biotin hydrazide. The relationship between the chemoresistive change and the binding of avidin‐biotin moieties in the polymer is observed in the output and on/off characteristics of the OTFTs. The exposure of the OTFTs to avidin causes a lowering of ID at VD = ‐40 V and VG = ‐40 V of nearly five orders of magnitude.