Label-free biosensors attempt to overcome the stability and reliability problems of biosensors relying on the detection of labeled molecules. We propose a label-free biosensor based on microring cavities in Silicon-on-Insulator (SOI) that fits in an area below 10x10mum(2). The resonance wavelength shift that occurs when the surroundings of a cavity is changed, is used for sensing. While theoretically the performance for bulk refractive index changes is moderate (10(-5)), this device performs outstanding in terms of absolute molecular mass sensing (theoretical sensitivity of 1fg molecular mass) thanks to its extremely small dimensions. We use the avidin/biotin high affinity couple to demonstrate good repeatability and detection of protein concentrations down to 10ng/ml. Fabrication with Deep UV lithography allows for cheap mass production and integration with electronic functions for complete lab-on-chip devices.

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The paradigm of the green economy has contributed to raising the attention paid to developing sustainability-oriented strategies for supply chain (SC) management. The responsibility of producers to extend and reverse SCs is a critical and timely topic that captures increasing concerns over the way firms can adapt their business models to interlinking technical, socioeconomic and environmental frameworks. This is particularly true when producers are not also reuse/recycle actors. By performing a critical review of the scientific literature on this field, this article develops nine elemental factors that can be considered for assessing the impacts of collaborative strategies as a means to implement extended producer responsibility (EPR) in open-loop SCs. The resulting conceptual framework provides EPR implementation guidance under different market conditions. Inter-organizational relationships are found to present both opportunities and threats that can be profitably managed under a systemic perspective. \ud Implications for management and needs for further research are discussed