A fluorescence sensor for Ag(I) ions is developed based on the target-induced conformational change of a silver-specific cytosine-rich oligonucleotide (SSO) and the interactions between the fluorogenic SSO probe and graphene oxide.

Edited by Lev KisselevAbstract The small molecule coralyne was found to bind preferentially and strongly to single-stranded poly(A) with an apparent association constant (K a ) of (1.8 ± 0.3) · 10 6 M À1 . Binding of coralyne to poly(A) is predominantly enthalpically driven with a stoichiometry of one coralyne per four adenine bases. Poly(A) forms a coralyne dependent secondary structure with a melting temperature of 60°C, for the conditions of our study.

Pressure sensor is one of the most fascinating and important components of E-skin that possesses unique abilities to imitate, enhance, and replace the human's tactile sensation. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] Among the different kinds of pressure sensors, [17][18][19][20][21][22][23][24][25][26][27][28][29][30] piezoresistive sensors generally have simple structures and easy read-out characteristics, which make them highly promising for application. [31][32][33][34] However, on the other hand, the simple output signal (current or resistance) presents difficulty to identify the complex and multiple stimuli. As for the organic field-effect transistor (OFET)-based sensors, the unique current amplification function of transistor makes it ideal candidate for sensing weak signals, and their multiple output parameters (source-drain current, threshold voltage, current on/off ratio, subthreshold swing) enable it to distinguish complex signals. [35][36][37] Furthermore, every component of OFETs including gate electrode, dielectric layer, semiconductor layer, and drain/source electrodes can be probably used as active layer of sensors, [38,39] which provides more possibilities for integration of multiple sensing. [40][41][42][43][44] In some reported sensors, tuning dielectric capacitance of OFET by pressure is mainly used as the basic working principle. Bao and co-workers pioneered in using microstructured poly(dimethylsiloxane) (PDMS) as dielectric of OFET for sensing pressure with sensitivity of 0.55 kPa −1 . [22] Zhu and co-workers utilized a suspended gate for construction of pressure sensor with sensitivity of 192 kPa −1 . [30] However, the tuning of capacitance in OFET may suffer from the risk of impurity or breakdown. As stated above, all components of OFET might be used for the pressure sensors, but OFET-based pressure sensors using semiconductor and source/ drain electrodes have not been reported so far.In OFETs, the contact interface between semiconductor and source/drain electrodes determines the charge injection efficiency and thus greatly influences the device performance, which therefore provides a model for pressure sensing if the contact quality can be tuned by pressure with an appropriate device structure. Piezoresistive sensor with roughened contact interface provides inspiration, but the active components of conventional piezoresistive sensor generally consist of one or more kinds of conducting materials since the low bulk resistivity of conducting materials may enable the contact resistance to dominate the sensor device and therefore produce The piezoresistive pressure sensor, a kind of widely investigated artificial device to transfer force stimuli to electrical signals, generally consists of one or more kinds of conducting materials. Here, a highly sensitive pressure sensor based on the semiconductor/conductor interface piezoresistive effect is successfully demonstrated by using organic transistor geometry. Because of the efficient combination of the piezoresistive effect and f...

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