Surface plasmon resonance optical sensor for determination of caffeine

Ajeman, Habibuzzikri (2022) Surface plasmon resonance optical sensor for determination of caffeine. [Project Paper] (Submitted)

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Abstract

Caffeine is one of the organic compounds that always have been used in food, beverages, powder, capsules and medicines. Caffeine consumption have many benefits such as increase alertness, easing fatigue and elevated blood pressure. Excessive caffeine intake can bring harm towards body. In this study, 3,5-diaminobenzoic acid (DIABA) and nanocellulose crystalline (NCC) has been used as sensing materials to detect caffeine using surface plasmon resonance (SPR) technique. Next, DIABA, NCC and DIABA/NCC thin film have been prepared by using spin coating technique at 5000 rev/min for 30 minutes. Gold thin film, gold thin film coated with DIABA and NCC separately found no change in resonance angle. It showed that no change for refractive index for all different caffeine concentrations. The used of gold modified by DIABA/NCC thin film with ratio 2:1 showed positive responses towards different caffeine concentrations as low as 0.5 nM. The SPR curves shifted to the left as the concentration increases. The sensor produced a linear response for caffeine with sensitivity of 0.05629 nM−1 and affinity constant value of 0.6655 M−1 0.6655 M−1. The full width half maximum (FWHM) value was 2.96°, 2.99°, 3.04°, 3.05°, 3.06°, 3.04°, 3.02° and 3.21°. These produced the highest detection accuracy (DA) is 0.34/° at 0 nM and the lowest is 0.31/° at 100 nM. Thus, gold modified by DIABA/NCC thin film shows a good potential for detection of caffeine by using SPR.

Item Type:	Project Paper
Faculty:	Fakulti Sains
Depositing User:	Ms. ROHANA ALIAS
Date Deposited:	25 Jun 2024 10:21
Last Modified:	25 Jun 2024 10:21
URI:	http://psaspb.upm.edu.my/id/eprint/1993

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