BUKU ABSTRAK - Universiti Putra Malaysia

Web-based GIS Application for Selecting Optimal Road and Bus Modelling for
UPM
Assoc. Prof. Dr. Abdul Rashid Mohamed Shariff
Mubarak Abdul Fattah Abdul Munim, Nik Norasma Che’ya, and Ebrahim Jahanshiri
Institute of Advanced Technology, University Putra Malaysia,
43400 UPM Serdang, Selangor, Malaysia.
+603-8946 7543; rashidpls@gmail.com
An Enzyme-based Biosensor for Determination of Formaldehyde in Fish and Fish
Products
Assoc. Prof. Dr. Fatimah Abu Bakar
Nur Indang Marzuki, Abu Bakar Salleh, Nor Azah Yusof and Lee Yoke Heng
Institute of Bioscience, University Putra Malaysia,
43400 UPM Serdang, Selangor, Malaysia.
+603-8946 8375; fatim@putra.upm.edu.my
191
Science, Technology & Engineering
Nowadays, web-based GIS application plays a significant role to carry out a lot of services for public users and
become increasingly popular for solving problems and making decisions. This project outlines the development
of web-based application to serve a student’s needs. Some of students’ needs are to find out a particular location
especially in a big area such as UPM University, and getting the optimal route between two addresses to minimise
the time and effort. In addition, to obtain the best and alternative solutions in bus system decision making. Using
ArcGIS Server for Microsoft .NET framework with its capability in network analysis and ASP.NET, the webbased
has the ability to determine the optimal route and build custom interface for UPM bus services to interact
with students easily and effectively. This is of great help for improvement in transit services for students.
Keywords: Optimal route, web-based GIS, student bus transportation, network analysis, bus route networking
Formaldehyde (FA) is often used in fishery industry as preservative to maintain its freshness and prevent
microbial spoilage. However, it is harmful for human consumption when used in excess as the residues retained
in the fish muscles although it has been cooked, roasted or boiled. Several methods such as Nash method, HPLC,
GC-MS, bio-sniffer and electronic nose have been used for determination of formaldehyde. Nevertheless, these
methods involved long hours, toxic reagents and maybe interrupted by interferences, resulted biases in analysis
and not suitable for real-time measurements. Thus, an enzyme-based biosensor was developed for formaldehyde
determination comprising three electrodes; working electrode, reference electrode and counter electrode, wherein
formaldehyde dehydrogenase immobilised in Nafion polymer through entrapment technique by drop coating
method on the surface of the working electrode. A method for formaldehyde determination is conducted by
applying samples which contain formaldehyde in the biosensor and the results are obtained by measuring the
current changes as the output signal at the constant voltage, referring the presence of formaldehyde.The enzyme
solution is prepared by dissolving the appropriate amount in 0.1 M of phosphate buffer at different pH ranging
from 6.5 to 8.5, with optimum pH of 8. Immobilization of the enzyme is done by mixing the solution with Nafion
polymer at different ratio (1:10,1:20, 1:30, 1:40 and 1:50) by retaining the amount of the enzyme volume as the
enzyme is expensive to be used in bulk. The optimum ratio is at 1:20. The mixture is then sonicated for 15 min to
homogenise and to make sure the immobilisation of enzyme in the polymer to occur completely. The mixture is
then stored at 4 o C after or before being used to avoid the denaturation of the enzyme. The system can detect 0.01
to 20ppm formaldehyde and is stable for up to six months and retains 90% of response.
Keywords: Enzyme-based biosensor, formaldehyde, formaldehyde dehydrogenase, fish, nafion polymer