Glucose sensors rely on specific enzymes as bioreceptors to detect glucose levels accurately. The correct answer is both glucose oxidase and glucose dehydrogenase, widely used in commercial devices.

Correct Answer

(4) Both 1 and 3

Glucose oxidase (GOx) and glucose dehydrogenase (GDH) serve as primary bioreceptors in electrochemical glucose biosensors. GOx produces hydrogen peroxide during glucose oxidation, detectable via amperometry, while GDH generates electrons directly without oxygen interference, improving accuracy in varying conditions.

Option Breakdown

(1) Glucose Oxidase

GOx is the gold standard bioreceptor, catalyzing β-D-glucose oxidation to gluconolactone and H₂O₂ using FAD as cofactor. Its high glucose selectivity and stability make it ideal for self-monitoring blood glucose (SMBG) strips, though oxygen-dependent.

(2) Glucose Kinase

Also called glucokinase or hexokinase, this phosphorylates glucose to glucose-6-phosphate but requires ATP and is not specific enough for biosensor transduction. It lacks the redox properties needed for direct electrochemical detection in glucose sensors.​

(3) Glucose Dehydrogenase

GDH, often FAD- or PQQ-dependent variants, oxidizes glucose while transferring electrons to mediators, avoiding H₂O₂ and oxygen issues. It’s favored in modern sensors for hematocrit independence and use in neonatal testing.

(4) Both 1 and 3

Correct. Both GOx and GDH dominate commercial glucose biosensors due to complementary strengths—GOx for selectivity, GDH for interference resistance. Many devices choose based on application needs.