Clinical and food biochemistry: Which device is specifically designed to quantify hypoxanthine levels (for example, in freshness testing or purine metabolism studies)?

Introduction / Context:
Hypoxanthine arises from ATP breakdown and purine metabolism. Its accumulation is a marker for tissue freshness (for example, fish quality) and metabolic status. Biosensors targeting hypoxanthine often use xanthine oxidase or related enzyme cascades coupled to electrochemical transducers.

Given Data / Assumptions:

• We need a device tailored to detect hypoxanthine.
• Other listed sensors target different analytes (urea, ethanol) or general parameters (pH).
• Specific recognition is essential for analytical selectivity.

Concept / Approach:
A hypoxanthine biosensor employs biochemical recognition (enzymes) and transduction (amperometry, potentiometry, optical) to convert the presence of hypoxanthine into a measurable signal. Non-specific devices (like a generic ISFET) lack the required biochemical specificity without additional functionalization.

Step-by-Step Solution:

Verification / Alternative check:
Published hypoxanthine sensors use enzymatic conversion to hydrogen peroxide or related products, detected electrochemically, validating specificity.

Why Other Options Are Wrong:

Common Pitfalls:
Assuming any electrochemical sensor measures any metabolite; specificity comes from the biorecognition layer.

Final Answer:
A dedicated hypoxanthine sensor (enzyme/electrochemical based).