The fabrication of acid functionalized multi-walled carbon nanotube (fMWCNT) combined apple tissue based amperometric biosensor through a cross-linking agent-free approach has been presented for the phenol detection in this study. Apple tissue entrapped in fMWCNT-glassy carbon paste composite was employed as the natural polyphenol oxidase source for the enzymatic oxidation of phenol and the consumption of the dissolved oxygen was monitored via chronoamperometry as the biosensor response. The effect of experimental parameters (e.g. working potential, pH and tissue amount) were examined to obtain the optimum measurement conditions. Under optimized conditions, amperometric responses linearly increased in the range of 10-200 µM phenol and limit of detection was calculated as 3.26 µM (n=3). Apple tissue based biosensor was utilized for the phenol detection in tap water samples by serving satisfying recovery values.