A cost-effective and simple biosensor was developed for the accurate and rapid monitoring of norovirus GII in a sample. The modified DNA aptamer, 5 guanines linked to conventional DNA aptamer, designed for the research, was able to rapidly capture norovirus GII in tap water as well artificial urine. In addition, the extra guanines of the modified DNA aptamer enhanced the sensitivity of biosensor with guanine chemiluminescence detection based on the principle of intra chemiluminescent resonance transfer (Intra-CRET). This is because additional high-energy intermediates formed from the reaction of extra guanines and 3, 4, 5-trimethoxylphenylglyoxal (TMPG) were able to directly transfer energy to 6-carboxylfluorescein (6-FAM) to emit bright chemiluminescence. The biosensor operated without time-consuming and tedious procedures (e.g., sample pretreatment, long and multiple incubations, washings) was able to accurately quantify trace levels of norovirus GII capsid with excellent specificity and reproducibility. The limit of detection (LOD = 3σ) of the biosensor for norovirus GII capsids in tap water was as low as 80 ng/ml. It is expected that the new technology confirmed while developing the biosensor can be applied to devise alternative biosensors capable of rapidly quantifying various food-borne pathogens in a sample.