Sains Malaysiana 32: 47-56 (2003)                                                                                                Sains Fizis dan Gunaan/

Physical & Applied Science

Biosensor Potentiometrik untuk Penentuan Urea

dan Ketoksikan Logam Berat

(Potentiometric biosensor for determination of

urea and toxicity of heavy metal)

Lee Yook Heng, Loh Han Chern & Musa Ahmad

Pusat Pengajian Sains Kimia & Teknologi Makanan   

Fakulti Sains Dan Teknologi

Universiti Kebangsaan Malaysia

43600 UKM Bangi, Selangor D.E., Malaysia

ABSTRAK

Kajian reka bentuk biosensor potentiometrik untuk penentuan urea telah dilakukan dengan menggunakan membran metakrilat-akrilat sebagai matriks pemegunan. Dua jenis membran telah digunakan iaitu membran metakrilat­akrilat dengan komposisi metil metakrilat: n-butil akrilat = 2:8 yang digunakan dalam pemegunan ionofor H⁺ untuk pengesanan ion hidrogen dan membran polihidroksil etilmetakrilat yang digunakan untuk pemegunan enzim urease. Penggandingan kedua-dua membran ini dengan transduser potentiometrik dapat menghasilkan biosensor urea yang boleh digunakan untuk penentuan urea dalam pelbagai julat kepekatan bergantung kepada muatan larutan penimbal yang digunakan. Di samping itu, kajian terhadap kemungkinan biosensor urea dapat digunakan dalam analisis logam berat dan ketoksikan logam di persekitaran turut dilakukan.

ABSTRACT

A potentiometric biosensor for urea has been designed based on methacrylic­acrylic membranes as matrices for immobilisation. Two types of membranes were used: methacrylic-acrylic membranes with the composition of methyl methacrylate: n-butyl acrylate = 2:8 was used for the immobilisation of a H⁺ ionophore whilst a polyhydroxyl ethylmethacrylate membrane was employed for the immobilisation of the urease enzyme. By coupling these two mem­branes with a potentiometric transducer, a workable biosensor for the determination of various concentrations of urea, depending on the buffer capacity was designed. The possibility of utilising this biosensor for the detection of heavy metals and analysis of environmental toxicity of metals through inhibition of the urease enzyme was alsoexplored.

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