Diazo-reaction based dual-mode colorimetric-electrochemical sensing of nitrite in pickled food

3materials

4samples

2synthesis routes

13measurements

67results

6claims and caveats

Evidence map

Open a family to keep every result attached to its sample, method and conditions.

Sensing Application6 measurements35 results →Electrochemistry Application4 measurements24 results →Spectroscopy1 measurement5 results →Microscopy Morphology1 measurement2 results →Diffraction Structure1 measurement1 result →

Author interpretations and caveats

Paraphrased for this database from the authors’ stated interpretations — never quoted verbatim — and kept separate from reported measurements.

Application RelevanceSupport assessment: High

The electrochemical mode is more sensitive than the colorimetric mode, with a lower nitrite LOD of 5.4e-7 mol L-1 versus 8.5e-6 mol L-1.

1 · Abstract · Linked to 2 structured results

CaveatSupport assessment: High

No first-hand intrinsic MOF electrical conductivity, carrier transport, thermoelectric or BET porosity result is reported; conductive behaviour is inferred from EGP support in an electrochemical sensor.

Caveat: Relevant to core_transport_physics classification.

1-6 · Abstract through Conclusions

Composite RoleSupport assessment: High

The multilayer EGP substrate increases Cu-MOF loading, provides a conductive backbone for electroanalysis, and allows the Cu-MOFs/EGP to be used directly as the working electrode.

Caveat: The paper asserts superior electrical conductivity of EGP but does not report a direct conductivity measurement.

1 and 5 · Abstract; 3.3 Electrochemical sensing performance study · Linked to 2 structured results

Phase AssignmentSupport assessment: Medium

XRD, FTIR and elemental mapping support successful synthesis of Cu-MOFs on EGP, although the Cu-MOF is incompletely crystallised and no exact framework formula/topology is reported.

Caveat: The phase assignment relies on characteristic peaks and elemental mapping rather than a solved crystal structure.

3 · 3.1 Characterization of Cu-MOFs/EGP · Fig. 1 and Fig. 2 · Linked to 3 structured results

Structure Property LinkSupport assessment: High

Cu-MOFs/EGP displays oxidase-like activity that converts TMB to oxTMB, whereas EGP alone shows no obvious oxidase-like response.

4 · 3.2 Colorimetric sensing performance study · Fig. 3A · Linked to 2 structured results

Transport MechanismSupport assessment: High

Nitrite detection is attributed to a diazotization reaction between NO2- and oxTMB, producing a color change and a ratiometric electrochemical signal.

Caveat: This is an application mechanism rather than intrinsic electronic transport in the MOF.

4-5 · 3.2 and 3.3 · Fig. 3C-D and Fig. 4B · Linked to 3 structured results

Material identities

Names and aliases are kept exactly within the paper’s own identity model.

Material	Composition	Structure context	Source
Cu-MOFs from Cu2+ and AMTA	Not specifiedCu2+ centres coordinated to AMTA; Cu-N bond assigned by FTIR · 3-amino-5-mercapto-1,2,4-triazole (AMTA)	unknown · PristineCu-MOF with incomplete crystallisation; characteristic XRD peak reported at 2theta = 30 degrees.	3 · 3.1 Characterization of Cu-MOFs/EGP · Fig. 2
Cu-MOFs/EGP composite	Not specifiedCu2+ centres in Cu-MOFs loaded on exfoliated graphite paper · AMTA	unknown · CompositeCu-MOF nanoparticles evenly distributed on exfoliated graphite paper.	1 · Abstract
Exfoliated graphite paper	C	2D · DerivedCorrugated multi-layer exfoliated graphite paper support.	3 · 3.1 Characterization of Cu-MOFs/EGP · Fig. 1A

Sample register

Sample form, processing state and composition status define the context for measurements.

Show 4 sample records

Sample	Form and role	Processing and geometry	Source
Cu-MOFs/EGPresearch_0650__mat__mat_cu_mof_egp	Electrode · Composite Sample · Composite	Cu-MOFs grown in situ on EGP in a Teflon-lined autoclave, washed with DMF and ethanol, and vacuum dried at 120 deg C overnight.exfoliated graphite paper	2-3 · 2.3 Synthesis of Cu-MOFs/EGP · Scheme 1
Cu-MOFs componentresearch_0650__mat__mat_cu_mof	Powder · Composite Component · Pristine Framework	Cu-MOF phase/component characterised by XRD and FTIR; isolation details are not separately described.	3 · 3.1 Characterization of Cu-MOFs/EGP · Fig. 2
Exfoliated graphite paper controlresearch_0650__mat__mat_egp	Electrode · Pristine Control · Derived Carbon	Graphite paper cleaned, dried and tape-peeled over a 0.5 cm x 1.5 cm geometric area.graphite paper	2 · 2.2 Pre-treatment of graphite paper
Pickled-food nitrite test system using Cu-MOFs/EGPresearch_0650__mat__mat_cu_mof_egp	Unknown · Model System · Model	Cantonese sausage, ham sausage, salted duck eggs and pickled vegetables pretreated, diluted where needed, and analysed with the Cu-MOFs/EGP sensor.	6 · 3.5 Analysis of real samples · Tables 1 and 2