Sensing Application — 3D Co-doped Ni-based conductive MOFs modified electrochemical sensor for highly sensitive detection of L-tryptophan

9 measurement groups · 37 results

Reported values remain attached to the sample, method, conditions, extraction quality and source location that produced them.

Cyclic voltammetry ratio optimisation

Voltammetry

Co-Ni-MOFs ratio-series/GCE electrodes · Electrode

Co-Ni-MOFs-0.1%/GCE, Co-Ni-MOFs-1%/GCE, Co-Ni-MOFs-2%/GCE and Co-Ni-MOFs-5%/GCE tested in 0.1 mol L^-1 PBS, pH 2.5, containing 0.1 mmol L^-1 L-tryptophan.

Geometry: modified GCE three-electrode setup
Context: Co/Ni ratio series electrodes
Measurement source: 2 · Supplementary figure captions · Fig. S3

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Best Co/Ni molar ratio for tryptophan sensingMarked as a best value within this paper	1% Co/Ni gave larger and stable oxidation peak current	—	—	Text Rounded Reported	6 · 3.2 · Fig. S3
Visual peak current for Co-Ni-MOFs-0.1%/GCE in ratio optimisation	about 4.0 uA at 0.1 mmol L^-1 L-tryptophan	—	visual estimate from rendered Fig. S3B axis	Visual Estimate Approximate	2 · Supplementary figure captions · Fig. S3B
Visual peak current for Co-Ni-MOFs-1%/GCE in ratio optimisationMarked as a best value within this paper	about 5.9 uA at 0.1 mmol L^-1 L-tryptophan	—	visual estimate from rendered Fig. S3B axis	Visual Estimate Approximate	2 · Supplementary figure captions · Fig. S3B
Visual peak current for Co-Ni-MOFs-2%/GCE in ratio optimisation	about 5.2 uA at 0.1 mmol L^-1 L-tryptophan	—	visual estimate from rendered Fig. S3B axis	Visual Estimate Approximate	2 · Supplementary figure captions · Fig. S3B
Visual peak current for Co-Ni-MOFs-5%/GCE in ratio optimisation	about 4.9 uA at 0.1 mmol L^-1 L-tryptophan	—	visual estimate from rendered Fig. S3B axis	Visual Estimate Approximate	2 · Supplementary figure captions · Fig. S3B

Cyclic voltammetry for L-tryptophan oxidation

Voltammetry

Co-Ni-MOFs-1%/GCE · Electrode

0.1 mmol L^-1 L-tryptophan in 0.1 mol L^-1 PBS, pH 2.5; comparison of Co-Ni-MOFs-1%/GCE, Ni-MOFs/GCE and bare GCE.

Geometry: modified GCE three-electrode setup
Context: target electrode with pristine and bare controls
Measurement source: 5-7 · 3.2 · Fig. 5A

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
L-tryptophan oxidation reversibility	no reduction peaks; completely irreversible electrocatalytic oxidation	—	—	Qualitative Qualitative	5 · 3.2 · Fig. 5A

Differential pulse voltammetry calibration

Voltammetry

Co-Ni-MOFs-1%/GCE · Electrode

0.1 mol L^-1 PBS, pH 2.5, containing L-tryptophan concentrations from 0.01 to 300 umol L^-1.

Geometry: modified GCE three-electrode setup
Context: target electrode
Measurement source: 7-8 · 3.5 · Fig. 7 and Table 1

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
DPV linear range lower boundMarked as a best value within this paper	0.01 umol L^-1	—	—	Text Exact Reported	7 · 3.5 · Fig. 7B
DPV linear range upper boundMarked as a best value within this paper	300 umol L^-1	—	—	Text Exact Reported	7 · 3.5 · Fig. 7B
DPV calibration R2Marked as a best value within this paper	R2 = 0.9995	—	—	Text Exact Reported	7 · 3.5 · Fig. 7B
DPV calibration slope	Ip = 0.0174C + 0.0538	—	—	Text Exact Reported	7 · 3.5 · Fig. 7B
Limit of detection for L-tryptophanMarked as a best value within this paper	8.7 nmol L^-1 (S/N = 3)	0.0087 umol L^-1	—	Text Exact Reported	7-8 · 3.5 · Table 1

DPV interference test

Voltammetry

Co-Ni-MOFs-1%/GCE · Electrode

Interferents tested against detection of 0.1 mmol L^-1 L-tryptophan.

Geometry: modified GCE three-electrode setup
Context: target electrode
Measurement source: 8-9 · 3.6 · Table 2

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Signal change with Ba2+	0.63% at 15 umol L^-1	—	—	Table Exact Reported	9 · 3.6 · Table 2
Signal change with Ca2+	0.05% at 15 umol L^-1	—	—	Table Exact Reported	9 · 3.6 · Table 2
Signal change with CO4^2- as printed in table	0.58% at 15 umol L^-1	—	—	Table Exact Reported	9 · 3.6 · Table 2
Signal change with dopamine hydrochloride	-0.48% at 5 umol L^-1	—	—	Table Exact Reported	9 · 3.6 · Table 2
Signal change with Glucose	0.28% at 10 umol L^-1	—	—	Table Exact Reported	9 · 3.6 · Table 2
Signal change with Hydroxylamine hydrochloride	0.02% at 5 umol L^-1	—	—	Table Exact Reported	9 · 3.6 · Table 2
Signal change with Luteolin	-0.37% at 5 umol L^-1	—	—	Table Exact Reported	9 · 3.6 · Table 2
Signal change with lysine	4.89% at 10 umol L^-1	—	—	Table Exact Reported	9 · 3.6 · Table 2
Maximum absolute signal change among listed interferents	4.89% for lysine	—	—	Table Exact Reported	9 · 3.6 · Table 2
Signal change with nitrite	0.31% at 5 umol L^-1	—	—	Table Exact Reported	9 · 3.6 · Table 2
Signal change with Pb2+	0.69% at 15 umol L^-1	—	—	Table Exact Reported	9 · 3.6 · Table 2

DPV pH optimisation

Voltammetry

Co-Ni-MOFs-1%/GCE · Electrode

0.1 mmol L^-1 L-tryptophan in 0.1 mol L^-1 PBS at pH 1, 2, 2.5, 3, 4 and 5.

Geometry: modified GCE three-electrode setup
Context: target electrode
Measurement source: 6-7 · 3.4 · Fig. 6

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Epa-pH slope	-45 mV pH^-1	—	—	Text Rounded Reported	6 · 3.4 · Fig. 6B
Optimal pH for L-tryptophan sensingMarked as a best value within this paper	pH 2.5	—	—	Text Exact Reported	6 · 3.4 · Fig. 6A

DPV recovery and mouse plasma analysis

Voltammetry

Co-Ni-MOFs-1%/GCE · Electrode

Simulated samples at 8, 60 and 100 umol L^-1; mouse plasma diluted 100-fold with pH 2.5 PBS and centrifuged at 12000 rpm before detection.

Geometry: modified GCE three-electrode setup
Context: target electrode
Measurement source: 9 · 3.7 · Table 3

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Mean L-tryptophan concentration in control mouse plasma	ca. 0.46 umol L^-1	—	—	Text Approximate	9 · 3.7 · Table 3
Mean L-tryptophan concentration in cadmium-treated mouse plasma	ca. 9.91 umol L^-1	—	—	Text Approximate	9 · 3.7 · Table 3
Simulated sample 1 recovery	found 7.95 umol L^-1 for 8.00 umol L^-1 added; recovery 99.38%	—	RSD 1.23%	Table Exact Reported	9 · 3.7 · Table 3
Simulated sample 2 recovery	found 59.85 umol L^-1 for 60.00 umol L^-1 added; recovery 99.75%	—	RSD 1.46%	Table Exact Reported	9 · 3.7 · Table 3
Simulated sample 3 recovery	found 101.9 umol L^-1 for 100.00 umol L^-1 added; recovery 101.96%	—	RSD 2.52%	Table Exact Reported	9 · 3.7 · Table 3
Control plasma standard-addition found concentration	30.46 umol L^-1 found after 30.00 umol L^-1 addition; RSD 13.43%	—	RSD 13.43%	Table Exact Reported	9 · 3.7 · Table 3
Cadmium-treated plasma standard-addition found concentration	39.91 umol L^-1 found after 30.00 umol L^-1 addition; RSD 2.05%	—	RSD 2.05%	Table Exact Reported	9 · 3.7 · Table 3

Inter-electrode reproducibility

Co-Ni-MOFs-1%/GCE · Electrode

Five Co-Ni-MOFs-1%/GCE sensors tested for oxidation peak current of 0.1 mmol L^-1 L-tryptophan.

Geometry: modified GCE three-electrode setup
Context: target electrode
Measurement source: 8 · 3.6 · Fig. 8B

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Reproducibility RSD across five electrodes	4.78%	—	—	Text Exact Reported	8 · 3.6 · Fig. 8B

Scan-rate dependent cyclic voltammetry

Voltammetry

Co-Ni-MOFs-1%/GCE · Electrode

0.1 mol L^-1 PBS with 100 umol L^-1 L-tryptophan; scan rates 20-500 mV s^-1.

Geometry: modified GCE three-electrode setup
Context: target electrode
Measurement source: 6-7 · 3.3 · Fig. 5B-D

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Electrons transferred in tryptophan oxidation	two electrons	—	—	Calculated From Reported Rounded Reported	6 · 3.3 · Fig. 5D
Epa versus log(scan-rate) slope	Epa = 0.055 log v + 1.74	—	—	Text Exact Reported	6 · 3.3 · Fig. 5D
Ipa versus square-root scan-rate slope	Ipa = 4.82 v^1/2 + 0.59	—	—	Text Exact Reported	6 · 3.3 · Fig. 5C
Ipa versus square-root scan-rate R2	R2 = 0.996	—	—	Text Exact Reported	6 · 3.3 · Fig. 5C

Long-term DPV stability

Voltammetry

Co-Ni-MOFs-1%/GCE · Electrode

DPV current of 0.1 mmol L^-1 L-tryptophan recorded every three days, five times, over about two weeks.

Geometry: modified GCE three-electrode setup
Context: target electrode
Measurement source: 8 · 3.6 · Fig. 8A

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Current retained after approximately two weeks	approximately 95% of original value	—	—	Text Approximate	8 · 3.6 · Fig. 8A