title: Surface modification of silicon dioxide, silicon nitride and titanium oxynitride for lactate dehydrogenase immobilization.
abstract: Three different types of surface, silicon dioxide (SiO2), silicon nitride (Si3N4), and titanium oxynitride (TiON) were modified for lactate dehydrogenase (LDH) immobilization using (3-aminopropyl)triethoxysilane (APTES) to obtain an amino layer on each surface. The APTES modified surfaces can directly react with LDH via physical attachment. LDH can be chemically immobilized on those surfaces after incorporation with glutaraldehyde (GA) to obtain aldehyde layers of APTES-GA modified surfaces. The wetting properties, chemical bonding composition, and morphology of the modified surface were determined by contact angle (CA) measurement, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM), respectively. In this experiment, the immobilized protein content and LDH activity on each modified surface was used as an indicator of surface modification achievement. The results revealed that both the APTES and APTES-GA treatments successfully link the LDH molecule to those surfaces while retaining its activity. All types of tested surfaces modified with APTES-GA gave better LDH immobilizing efficiency than APTES, especially the SiO2 surface. In addition, the SiO2 surface offered the highest LDH immobilization among tested surfaces, with both APTES and APTES-GA modification. However, TiON and Si3N4 surfaces could be used as alternative candidate materials in the preparation of ion-sensitive field-effect transistor (ISFET) based biosensors, including lactate sensors using immobilized LDH on the ISFET surface.
authors.affiliation: Department of Clinical Chemistry, Faculty of Medical Technology, Mahidol University, 999 Phutthamonthon 4 Road, Salaya, Phutthamonthon, NakhonPathom 73170, Thailand.
authors.forename: Pawasuth
authors.initials: P
authors.lastname: Saengdee
authors.affiliation: Thai Microelectronic Center (TMEC), Chachoengsao 24000, Thailand.
authors.forename: Woraphan
authors.initials: W
authors.lastname: Chaisriratanakul
authors.affiliation: Thai Microelectronic Center (TMEC), Chachoengsao 24000, Thailand.
authors.forename: Win
authors.initials: W
authors.lastname: Bunjongpru
authors.affiliation: Thai Microelectronic Center (TMEC), Chachoengsao 24000, Thailand.
authors.forename: Witsaroot
authors.initials: W
authors.lastname: Sripumkhai
authors.affiliation: Thai Microelectronic Center (TMEC), Chachoengsao 24000, Thailand.
authors.forename: Awirut
authors.initials: A
authors.lastname: Srisuwan
authors.affiliation: Thai Microelectronic Center (TMEC), Chachoengsao 24000, Thailand.
authors.forename: Wutthinan
authors.initials: W
authors.lastname: Jeamsaksiri
authors.affiliation: Thai Microelectronic Center (TMEC), Chachoengsao 24000, Thailand.
authors.forename: Charndet
authors.initials: C
authors.lastname: Hruanun
authors.affiliation: Thai Microelectronic Center (TMEC), Chachoengsao 24000, Thailand.
authors.forename: Amporn
authors.initials: A
authors.lastname: Poyai
authors.affiliation: Department of Clinical Chemistry, Faculty of Medical Technology, Mahidol University, 999 Phutthamonthon 4 Road, Salaya, Phutthamonthon, NakhonPathom 73170, Thailand. Electronic address: chamras.pro@mahidol.ac.th.
authors.forename: Chamras
authors.initials: C
authors.lastname: Promptmas
mesh_terms: D000327:Adsorption; D015374:Biosensing Techniques / Q000379:methods*; D004789:Enzyme Activation; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry; D005976:Glutaral / Q000737:chemistry*; D007770:L-Lactate Dehydrogenase / Q000737:chemistry*; D019344:Lactic Acid / Q000032:analysis / Q000737:chemistry*; D008422:Materials Testing; D011485:Protein Binding; D017655:Silicon Compounds / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D004800:Enzymes, Immobilized; D017655:Silicon Compounds; D019344:Lactic Acid; D012822:Silicon Dioxide; D007770:L-Lactate Dehydrogenase; C032734:silicon nitride; D005976:Glutaral
keywords: Immobilization; Lactate dehydrogenase; Silanization; Silicon dioxide; Silicon nitride; Surface modification; Titanium oxynitride