Search

© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Developing ultrasensitive chemical sensors with small scale and fast response through simple design and low-cost fabrication is highly desired but still challenging. Herein, a simple and universal sensing platform based on a hydrogel interferometer with femtomol-level sensitivity in detecting (bio)chemical molecules is demonstrated. A unique local concentrating effect (up to 109folds) in the hydrogel induced by the strong analyte binding and large amount of ligands, combined with the signal amplification effect by optical interference, endows this platform with an ultrahigh sensitivity, specifically 10−14m for copper ions and 1.0 × 10−11mg mL−1for glycoprotein with 2–4 order-of-magnitude enhancement. The specific chemical reactions between selected ligands and target analytes provide high selectivity in detecting complex fluids. This universal principle with broad chemistry, simple physics, and modular design allows for high performance in detecting wide customer choices of analytes, including metal ions and proteins. The scale of the sensor can be down to micrometer size. The nature of the soft gel makes this platform transparent, flexible, stretchable, and compatible with a variety of substrates, showing high sensing stability and robustness after 200 cycles of bending or stretching. The outstanding sensing performance grants this platform great promise in broad practical applications.

WOS: 000365525900060, We present the design, characterization, theoretical and experimental verification of a tunable perfect metamaterial absorber (MA) based electromagnetic (EM) energy harvesting and sensor application. We have used the golden ratio while determining the dimensions allowing a simple configuration and an easy fabrication for the proposed structure. We have examined and analyzed the perfect absorption (both numerically and experimentally) and EM energy harvesting (numerically) behaviors of the proposed structure in order to verify and show the characteristics of the model. It is shown that 99.9 % maximum absorption rate is achieved at 6.78 GHz, and MA structure can be used as an EM energy collector. In order to support the numerical study, an experimental study is realized. We have then developed a sensor application of the proposed MA structure and observed the effects of the harvesting system. Perfect MA sensor based EM energy harvesting system is successfully achieved.