Unique Organic–Inorganic Hybrid Copper(I) Phosphate with Ultralow Ractopamine Detection Limit and In Situ Sensing Ability

TL;DR

Scientists created a new hybrid material that can detect a drug in meat with extreme sensitivity, setting a new record for detection limits.

Contribution

The first organic–inorganic hybrid copper(I) phosphate material with an ultrasensitive ractopamine detection limit is synthesized.

Findings

NTOU-10@polypyrrole electrode achieved a detection limit of 3.31 × 10–19 M for ractopamine.

The material was successfully tested in spiked pork samples, proving its real-world applicability.

Integration into a flow injection analysis system enabled rapid and convenient detection.

Abstract

We successfully synthesized and characterized the first-ever
organic–inorganic
hybrid metal phosphate, NTOU-10, featuring lower-valence
copper nodes under hydrothermal conditions. The crystalline structure,
confirmed through single-crystal X-ray diffraction, thermogravimetric
analysis, solid-state NMR spectroscopy, X-ray photoelectron spectroscopy,
and bond valence-sum calculations, revealed its chemical composition,
and unique coordination bonding models between organic linkers, metal
nodes, and phosphate groups. These building blocks intricately bonded
through metal–oxygen and metal–nitrogen linkages to
form a highly complex crystalline structure. Taking innovation a step
further, we polymerized NTOU-10 with pyrrole to develop
the hybrid NTOU-10@polypyrrole (PPy) electrode, setting
a groundbreaking record with an ultrasensitive limit of detection
(LOD) of 3.31 × 10–19 M for ractopamine (RAC)
sensing, surpassing existing crystalline materials by more than 9
orders of magnitude. The real-world effectiveness of this biosensor
was demonstrated by detecting RAC in spiked pork samples. Additionally,
we integrated the NTOU-10@PPy electrode into a flow injection
analysis (FIA) system, offering advantages such as rapid detection,
minimal sample requirement, and operational convenience. This work
presents a significant leap forward in the design and synthesis of
novel materials, along with the development of a high-performance
biosensing platform for RAC detection.

The first-ever
crystalline organic−inorganic hybrid
metal phosphate incorporating lower-valence copper atoms as metal
nodes has been successfully synthesized under hydrothermal conditions.
This remarkable compound showcases a versatile range of coordination
types between organic linkers, metal nodes, and phosphate groups within
its crystalline structure. In a parallel breakthrough, we developed
a hybrid NTOU-10@polypyrrole electrode, leading to the
creation of a cutting-edge biosensor platform. This platform set a
new benchmark, achieving an unprecedented detection limit of 3.31
× 10−19 M for ractopamine, outshining any crystalline
material by over 9 orders of magnitude. With this innovation, we’ve
not only crafted a material with a unique structure and composition
but also opened new, efficient pathways for detection methods that
offer unparalleled convenience, speed, minimal analyte requirements,
and exceptional signal clarity and resolution.

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