Optical Properties and Kinetic Behaviour of Some Chemical and Biological Species Using Surface Plasmon Resonance Optical Sensor

Surface plasmon resonance (SPR) spectroscopy is a surface-sensitive technique that has been used to characterize the thickness and index of refraction of dielectric medium at noble metal interface. Nowadays surface plasmon resonance technique has emerged as a powerful technique for a variety of chemical and biological sensor applications. In this study, gold and silver with purity of 99.99% were used to fabricate thin metal films. The thin film was deposited onto a glass cover slip and attached onto the surface of a 60° prism using index matching oil. Liquid samples, such as chlorine, saccharide, swimming pool water, pesticide, virus and DNA were studied using Kretschmann Surface Plasmon Resonance technique. All the measurements were carried out at room temperature. The experiment was carried out by measuring the intensity of the optical reflectivity as a function of incident angle. It found that the shift of resonance angle (.dB) increased linearly with the sample concentration. The detection limit of the sensor was estimated better than 0.01 pM for the sample of DNA (Olig02-Bio). Larger sensor sensitivity of 9.42°/(mol/L) is obtained for the sucrose sample. The kinetic behaviour of the system was also examined to monitor the selfassembling p rocess on the metal surface in real time. The shift in resonance angle increased greatly with time during the increment of the molecules deposited on the gold surface. In contrast it was found decrease with time during self-assembling process. This work also studied the molecule-dielectric interaction for a thin Fatty Hydroxamic Acid (FHA) film (extract from crude palm oil), which the FHA layer was coated using spin coating on the top of metal film. When the medium outside the surface of Au film was changed from air to FHA layer, the resonance angle shifted to the higher value. The shift of resonance angle increased linearly with the increasing concentration FHA layer. When the metal ion was attached to the FHA film, the resonance angle was changed to the maximum value. The experimental results reveal that the technique that based on surface plasmon resonance phenomenon can be used to determine the optical properties and the kinetic behaviour. It also suitable to study the molecule-dielectric interaction for the polymer film. This technique can become an effective chemical optical sensor. Saccharide, pesticide and chlorine concentration in water can be detected using this sensor. Furthermore it also can be used to detect DNA and viruses solution

Optical properties and kinetic behavior of chlorine in pure water and swimming pool water using surface plasmon resonance technique

An optical sensor based on surface plasmon resonance phenomenon for detection of chlorine in pure water and swimming pool water is presented. The measurement was carried out at room temperature using Kretschmann surface plasmon resonance technique. When the air medium outside the metal film is changed to chlorine solution, the resonance angle shifted to the higher value. The shift of resonance angle (δθ) increases linearly with chlorine concentration in which the detection limit and sensor sensitivity could be quantified. In this work, the sensitivity of the detection was estimated to be 0.11°/ppm and 0.12°/ppm for Calcium Hypochlorite (G70) and Trichloroisocyanuric Acid (G90), respectively. The detection limit of this sensor is better than 0.1 ppm for chlorine samples and capable to monitor the chlorine concentration in swimming pool. We observed that the shift in the resonance angle (δθ) decreases with time due to reducing amount of chlorine in the solution. Result from real-time measurement of swimming pool water was compared with simulation result carried out in the laboratory. Both have shown that the resonance angle decreases with time due to releasing of chlorine gas to the atmosphere

Thermal Diffusivity Measurement of Abrasive Paper Using Photoacoustic Technique

Measurements of thermal diffusivity of two types of abrasive papers are reported. We have chosen silicon carbide and aluminium oxide abrasive papers as our samples. Thermal diffusivity of silicon carbide abrasive paper with the grit size of 320,360,400, 600, 800, 1000, 1200, and 1500 were measured. On the other hand, only two grit size (120 and 240) of aluminium oxide abrasive papers were chosen in the present experiments. All the measurements were carried out at room temperature with the abrasive surface facing the laser beam. The effective thermal diffusivity values obtained for silicon carbide are in the range of (5.1 - 8.9) x 10-2 cm2/s, which is lower than the value of thermal diffusivity of pellet ceramic silicon carbide prepared from silicon carbide powder. For aluminium oxide abrasive papers the effective value of thermal diffusivity (0.18 cm2/s dan 0.35 cm2/s) is higher than the value reported for aluminium oxide ceramic. The surface structure of the sample was investigated using SEM with the magnification of 100X

Optical properties and sugar content determination of commercial carbonated drinks using surface plasmon resonance

In this study, an optical sensor based on Kretschmann SPR technique was used to detect the sugar content in commercial carbonated drinks. Three samples of carbonated drinks labeled as "Coke", "100 Plus" and "F&N Orange" have been chosen for angle scan SPR measurements. All the measurements were carried out at room temperature using He-Ne laser beam (632.8nm, 5mW) as a light source. The commercially available carbonated samples were diluted by adding distilled water to produce solutions with different sugar content. The results show that the shift of resonance angle (δ;θSPP) increases linearly with the sugar content in which the detection limit and sensor sensitivity could be quantified. Therefore, this technique could be used as optical sensor for detecting sugar content in carbonated soft drinks

Effect of shock wave on constant load behaviour of Pb-Free/CNT solder joint

The constant load behaviour of SAC305 solder joint with addition of carbon nanotube (CNT), exposed to shock wave condition was investigated. Formulated SAC305-CNT solder pastes with 0.04 wt. % CNT were manually printed to the printed circuit board (PCB) with copper surface finish to form solder joint. The solder joint was exposed to the shock wave condition via open field blast air test using Trinitrotoluene (TNT) explosive. Nanoindentation approach was used to determine the constant load behavior of the SAC305-CNT solder joint under shock wave condition. The results showed that addition of CNT reduced the indentation depth of SAC305 solder joint at 10 mN peak load for blast test sample and control sample. Indentation depth displacement of SAC305-CNT solder joint for blast test sample and control sample were reduced about ~ 42 and ~56%, respectively, if compared to the SAC305 solder joint for blast test sample and control sample. SAC305-CNT solder joint was experienced minimal changes of stress exponent when exposed to the shock wave. The existence of CNT in the solder joint slows down the depth displacement due to constant load

Anodic and cathodic deposition of polyaniline films: a comparison between the two methods

This paper reports the comparison of polyaniline (PAni) thin films grown by anodic and cathodic electrodeposition. The growth condition, structure, optical property, thickness and morphology of the deposited layers have been characterized using cyclic voltammogram, x-ray diffraction (XRD), UV-vis spectroscopy, optical profilometry and scanning electron microscopy (SEM). The thin films grown from anodic deposition show blue-violet colour, which denotes pernigraniline fully oxidised state whereas the layers grown using cathodic deposition show pale yellow colour, which indicates leucoemeraldine fully reduced state of PAni. PAni grown from anodic deposition exhibit amorphous phase with cementing effect growth and bandgap varies from 3.90-4.08 eV. PAni layer from cathodic deposition demonstrated crystalinity based on the presence of the two XRD peaks at 2θ = 30.7° and 32.1° in the XRD pattern with random distribution of smaller grains and bandgaps in a range from 1.05 to 1.20 eV. The properties of PAni thin films electrodeposited from anodic and cathodic deposition and under a variety of deposition conditions have been compared and discussed in detail. © 2019 IOP Publishing Ltd

Kesan gelombang kejutan terhadap sifat mikromekanik sambungan pateri SAC 0307/ENiG menggunakan pendekatan pelekukan nano

Kebolehharapan dan kebolehtahanan pempakejan elektronik bagi peralatan elektronik dalam bidang ketenteraan adalah menjangkaui kepenggunaan komersial. Kebolehharapan sambungan pateri merupakan perkara asas bagi penilaian prestasi pempakejan elektronik. Ujian kebolehharapan komersial atau konvensional seperti dalam standard JEDEC (Solid State Technology Association) tidak dapat memenuhi keperluan pempakejan elektronik untuk piawaian ketenteraan. Kajian ini melaporkan gerak balas sambungan logam pateri SAC 0307 pada papan litar bercetak (PCB) dengan kemasan permukaan electroless nickel immersion gold (ENiG) terhadap gelombang kejutan hasil daripada ujian letupan secara terbuka. Perubahan sifat mikromekanik dikaji menggunakan pendekatan pelekukan nano. Gelombang kejutan yang berbeza dikenakan pada sambungan pateri dengan menggunakan bahan Emulex dengan dos sebanyak 700 g dan 1500 g. Kekerasan sambungan pateri telah menyusut sebanyak 29% daripada 141 MPa kepada 100 MPa selepas didedahkan pada gelombang kejutan dengan penggunaan dos Emulex sebanyak 1500 g. Modulus terkurang sambungan pateri juga telah menyusut sebanyak 13% daripada 141 GPa kepada 123 GPa dengan penggunaan dos bahan Emulex sebanyak 1500 g. Ujian gelombang kejutan telah menyebabkan berlakunya perubahan pada sifat mikromekanik sambungan pateri iaitu berlakunya kelakuan perlembutan yang melibatkan penyusutan nilai kekerasan dan modulus terkurang. Tiada retak diperhatikan pada antara sambungan pateri-substrat yang menunjukkan bahawa sambungan pateri adalah tidak gagal dan tetap utuh selepas didedahkan pada gelombang kejutan yang tinggi, walaupun berlaku penyusutan sifat mikromekanik yang ketara