Adsorption and covalent coupling of ATP-binding DNA aptamers onto cellulose.
With the long-term goal of developing paper surfaces that will detect pathogens, we have investigated physical adsorption and covalent coupling as strategies for treating cellulose surfaces with a DNA aptamer that binds ATP. Physical adsorption was reversible and the isotherms fitted the Langmuir equation with an adsorption maximum of 0.105 mg/m2 at high ionic strength (300 mM NaCl, 25 mM Tris-HCl) and only 0.024 mg/m2 in lower ionic strength buffer (25 mM Tris-HCl). Covalent coupling of amine-terminated aptamer with oxidized cellulose film (Schiff base + reduction) gave 25% coupling efficiency while maintaining the aptamer activity which was illustrated by using a known fluorescent aptamer that is capable of ATP detection. Therefore, covalent coupling, without spacer molecules, is a promising approach for supporting biosensing aptamers on cellulose.
Su
Shunxing
S
Department of Chemical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4L7, Canada.
Nutiu
Razvan
R
Filipe
Carlos D M
CD
Li
Yingfu
Y
Pelton
Robert
R
D000255:Adenosine Triphosphate / Q000737:chemistry*; D000327:Adsorption; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods; D002021:Buffers; D002482:Cellulose; D009994:Osmolar Concentration
D052157:Aptamers, Nucleotide; D002021:Buffers; D000255:Adenosine Triphosphate; D002482:Cellulose