An optimum copper concentration in environment is highly desired for all forms of life. We have developed an ultrasensitive copper sensor which functions from femto to micro molar concentration accurately (R² = 0.98). The sensor is based on denatured antibody immunoglobulin G (IgG), immobilized on polyaniline (PAni) which in turn is the coating on the core of an optical fiber. The sensing relies on changes in evanescent wave absorbance in the presence of the analyte. The sensor showed excellent selectivity towards Cu (II) ions over all other metal ions. The sensor was tested with lake and marine water samples to determine unknown concentrations of copper ions and the recovery results were within 90–115%, indicating reasonable accuracy. We further integrated the fiber-optic sensor with a miniaturized hand-held instrumentation platform to develop an accurate and field deployable device which can broadly be applicable to determine Cu (II) concentration in a wide range of systems – natural water bodies, soil as well as blood serum.

对于所有形式的生命，都非常希望在环境中达到最佳的铜浓度。我们开发了一种超灵敏的铜传感器，该传感器可以精确地实现从毫微微浓度到微摩尔浓度（R ²= 0.98）。该传感器基于变性抗体免疫球蛋白G（IgG），该抗体固定在聚苯胺（PAni）上，而聚苯胺又是光纤芯上的涂层。感测依赖于分析物存在时e逝波吸收率的变化。与所有其他金属离子相比，该传感器对Cu（II）离子具有出色的选择性。该传感器经过湖水和海水样品测试，以确定未知浓度的铜离子，回收率在90–115％之内，表明其准确性较高。我们进一步将光纤传感器与小型手持式仪器平台集成在一起，以开发一种可在现场部署的精确设备，该设备可广泛用于确定各种系统（天然水体，土壤以及水中）中的Cu（II）浓度。作为血清。