Clinical and food biochemistry: Which device is specifically designed to quantify hypoxanthine levels (for example, in freshness testing or purine metabolism studies)?
-
AA dedicated hypoxanthine sensor (enzyme/electrochemical based)
-
BAmorphous silicon ISFET (generic pH sensing without specificity)
-
CUrea sensor (measures urease activity, not purine metabolites)
-
DAlcohol sensor (ethanol-specific)
-
EGeneric temperature probe
Answer
Correct Answer: A dedicated hypoxanthine sensor (enzyme/electrochemical based)
Explanation
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:
Identify the analyte: hypoxanthine (purine derivative).Match analyte to sensor with appropriate biorecognition element.Select the dedicated hypoxanthine sensor as the correct instrument.Verification / Alternative check:Published hypoxanthine sensors use enzymatic conversion to hydrogen peroxide or related products, detected electrochemically, validating specificity.
Why Other Options Are Wrong:
ISFET: pH-sensitive; not selective for hypoxanthine unless heavily modified.Urea or alcohol sensors: different substrates and enzymes.Temperature probe: unrelated to analyte concentration.Common Pitfalls:Assuming any electrochemical sensor measures any metabolite; specificity comes from the biorecognition layer.
Final Answer:A dedicated hypoxanthine sensor (enzyme/electrochemical based).