SPR sensor for detection of heavy metal ions: Manipulating the EM waves polarization modes

Abstract

Water contamination by heavy metals is a common issue encountered in many countries due to industrial and urban wastes in water resources which give health and socio-economic impacts. This work is carried out to investigate the effect of EM wave polarization modes on the sensing properties of surface plasmon resonance (SPR) sensor in detecting heavy metal ions namely mercury (Hg) and plumbum (Pb). Three types of polarization modes such as p-polarized, s-polarized and circular-polarized light were introduced. Gold and silver thin films with thicknesses of 50nm were deposited on top of SPR layer system to excite surface plasmon polaritons (SPPs). The SPR curves were analyzed by studying the FWHM, Q-factor and angle shifting characteristics. We manage to prove theoretically that the SPR phenomena able to be created by using not only the p-polarized light, yet by employing a circular-polarized light. The sensor shows positive respond for both polarization modes, where the troughs were red-shifted about 23.78% as Pb was introduced on the top of the gold-coated SPR sensor. The SPR angles were shifted about 24.45% as the sensor was exposed with Hg metal ions. Different response due to the presence of different analytes exhibits an excellent criteria of high selectivity sensor. In conclusion, the combination of p-polarized light or circular-polarized light and gold thin film able to accentuate the significant role of SPR sensor in detecting heavy metal ions.

Optical Properties of Fe3O4/Chitosan and Its Applications for Signal Amplifier in Surface Plasmon Resonance Sensor

“…The SPR-sensor uses a Kretschmann configuration equipped with BK7 prims. The prism was deposited by gold with a dielectric constant of -9.39 ± 1.09i for the thickness of 50 nm [33]. On this configuration, we used three systems., e.g., prism/Au/air; prism/Au/Fe3O4/air; and prism/Au/Fe3O4-chitosan/air.…”

Sensitivity Optimization of Au/Ti Based-SPR Sensor by Controlling Light Incident Wavelength for Gas Sensing Application

“…According to Sharma et al (2007), the phenomena of SPR originated from Zenneck when he formulated a special surface wave solution to Maxwell's equations [16]. Sensors based on SPR have been widely developed since then in various fields and applications such as gas sensing [17], temperature sensing [18], urea detection [19], Escherichia coli (E-coli) identification [20], food quality [21] and monitoring water quality [22] [23].…”

Quantification of silver in several samples using a new ionophore polymer membrane as an optical sensor

“…or chemical (covalent bond) methods. 18 Porous, membranes, having the ability for separation, are widely used in water treatment. Many optical chemical sensors utilize colored complexes or reducing and oxidizing reagents immobilized on a membrane of a suitable polymer.…”