caa a22 4500 445880015 CHVBK 20180317145539.0 cr unu---uuuuu 170323e20111201xx s 000 0 eng 10.1007/s00604-011-0686-0 doi (NATIONALLICENCE)springer-10.1007/s00604-011-0686-0 Overcoming the adverse effects of crosslinking in biosensors via addition of PEG: Improved sensing of hydrogen peroxide using immobilized peroxidase [Elektronische Daten] [Mohammed ElKaoutit, Ignacio Naranjo-Rodriguez, Manuel Dominguez, Jose Hidalgo-Hidalgo de Cisneros] Glutaraldehyde (GA) is widely used as a crosslinker to immobilize enzymes, for examples in biosensors, but often causes partial denaturation. We find that the proper use of poly(ethylene glycol) (PEG) during the crosslinking process can fully preserve the native state and activity of horseradish peroxidase (HRP). An amperometric biosensor was developed based on these findings for the direct determination of hydrogen peroxide. UV-Vis and FTIR spectroscopy reveal that the HRP entrapped in a polypyrrole matrix retains its native structure. The addition of PEG increases the sensitivity and stability of the biosensor and prevents many of effects caused by intra-crosslinking via GA. The biosensor was operated at a potential of −350mV (vs Ag/AgCl) without any mediator and gave a linear response to H2O2 in the 5 to 190μM concentration range. The apparent Michaelis-Menten constant is 3.37mM, and maximal current is as high as 3.43μA. The surface of the biosensor was characterized by atomic force microscopy operated in the tapping mode. Figure Solid phase and AFM images of native and denaturized peroxidase Springer-Verlag, 2011 Direct electrocatalysis nationallicence Heme enzyme nationallicence Polyethylene glycol nationallicence Glutaraldehyde nationallicence Intra-crosslinkage nationallicence Conformational study nationallicence ElKaoutit Mohammed Departamento de Química Analítica, Facultad de Ciencias, Universidad de Cádiz, 11510, Puerto Real, Cádiz, Spain aut Naranjo-Rodriguez Ignacio Departamento de Química Analítica, Facultad de Ciencias, Universidad de Cádiz, 11510, Puerto Real, Cádiz, Spain aut Dominguez Manuel Departamento de la Física de la Materia Condensada, Facultad de Ciencias, Universidad de Cádiz, 11510, Puerto Real, Cádiz, Spain aut Hidalgo-Hidalgo de Cisneros Jose Departamento de Química Analítica, Facultad de Ciencias, Universidad de Cádiz, 11510, Puerto Real, Cádiz, Spain aut Microchimica Acta Springer Vienna 175/3-4(2011-12-01), 241-250 0026-3672 175:3-4<241 2011 175 604 https://doi.org/10.1007/s00604-011-0686-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00604-011-0686-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- ElKaoutit Mohammed Departamento de Química Analítica, Facultad de Ciencias, Universidad de Cádiz, 11510, Puerto Real, Cádiz, Spain aut NATIONALLICENCE 700 1- Naranjo-Rodriguez Ignacio Departamento de Química Analítica, Facultad de Ciencias, Universidad de Cádiz, 11510, Puerto Real, Cádiz, Spain aut NATIONALLICENCE 700 1- Dominguez Manuel Departamento de la Física de la Materia Condensada, Facultad de Ciencias, Universidad de Cádiz, 11510, Puerto Real, Cádiz, Spain aut NATIONALLICENCE 700 1- Hidalgo-Hidalgo de Cisneros Jose Departamento de Química Analítica, Facultad de Ciencias, Universidad de Cádiz, 11510, Puerto Real, Cádiz, Spain aut NATIONALLICENCE 773 0- Microchimica Acta Springer Vienna 175/3-4(2011-12-01), 241-250 0026-3672 175:3-4<241 2011 175 604 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer