Synthesis · Construction of a portable and sensitive electrochemical immunosensor for the rapid detection of erythromycin based on semiconductive bimetallic MOF

4 structured synthesis routes

Completeness describes how fully the route could be reconstructed from the main article and supporting information.

Partial recipeSource: SI

Route 1: Other

S5 · S1.4 Preparation of the screen-printed electrode (SPE)

SolventsTurpentine alcohol and methanol are listed as purchased reagents for ink/device preparation; exact ink formulation not given.

AdditivesGraphene nanosheets, multi-walled carbon nanotubes, Ag/AgCl paste, ethyl cellulose.

AtmosphereStored at room temperature under vacuum after annealing.

Temperature40

Time1

Substrate orientationPolyimide substrate; graphene/MWCNT ink printed as working and counter electrodes, Ag/AgCl paste as reference electrode.

Work-upSilk-screen printed using a temperature-controlled vacuum suction cup; annealed at 40 C for 1 h on a hotplate; stored under vacuum at room temperature.

Activationnot reported

Scalability contextSI describes large-area SPE manufacture by silk-screen printing.

Show 6 structured reagent records

Role	Reagent	Amount / concentration	Source
Other	graphene/MWCNTs nanocomposite ink	small amount	S5 · S1.4 Preparation of the screen-printed electrode (SPE)
Other	Ag/AgCl paste ink	printed as reference electrode	S5 · S1.4 Preparation of the screen-printed electrode (SPE)
Other	polyimide substrate	Not specified	S5 · S1.4 Preparation of the screen-printed electrode (SPE)
Additive	ethyl cellulose	Not specified	S5 · S1.4 Preparation of the screen-printed electrode (SPE)
Solvent	turpentine alcohol	Not specified	S5 · S1.4 Preparation of the screen-printed electrode (SPE)
Solvent	methanol	Not specified	S5 · S1.4 Preparation of the screen-printed electrode (SPE)

Complete recipeSource: Both

Route 2: Drop Cast

p.3 · 2.2. Fabrication of the CuxFe3-x(HHTP)2-based immunosensor · Scheme 1

SolventsMilli-Q water for MOF suspension; PBS (0.01 M, pH 7.4) for washing; graphene/MWCNT and Ag/AgCl inks used to prepare the SPE

AdditivesERY antibody solution, 100 ng mL-1; bovine serum albumin (BSA), 1.0 wt%; graphene nanosheets, MWCNTs, Ag/AgCl paste, turpentine alcohol and ethyl cellulose for SPE ink preparation

Atmosphereair drying at room temperature; as-prepared SPE stored at room temperature under vacuum

Temperature40

Time1 for SPE anneal; 0.667 antibody incubation; 0.5 BSA blocking

Substrate orientationPolyimide substrate with screen-printed carbon working/counter electrodes and Ag/AgCl reference; 5 uL MOF suspension drop-cast on SPE working surface

Work-upSPE printed on polyimide and annealed at 40 C for 1 h; 5 uL CuxFe3-x(HHTP)2 suspension drop-cast, washed with PBS three times and air dried; incubated with antibody for 40 min, rinsed with PBS; blocked with BSA for 30 min and rinsed with PBS; store final immunosensor at 4 C.

Activationnot reported

Scalability contextPortable SPE format and smartphone reader are emphasised; SI reports large-area SPE fabrication by silk-screen printing.

Show 7 structured reagent records

Role	Reagent	Amount / concentration	Source
Other	CuxFe3-x(HHTP)2 suspension	5 uL · optimised to 5.0 mg mL-1; tested 2.0, 3.0, 4.0, 5.0 and 6.0 mg mL-1	p.3 · 2.2. Fabrication of the CuxFe3-x(HHTP)2-based immunosensor · Scheme 1
Solvent	Milli-Q water	Not specified	p.3 · 2.2. Fabrication of the CuxFe3-x(HHTP)2-based immunosensor · Scheme 1
Other	antibody solution	100 ng mL-1	p.3 · 2.2. Fabrication of the CuxFe3-x(HHTP)2-based immunosensor · Scheme 1
Other	bovine serum albumin (BSA) solution	1.0 wt%	p.3 · 2.2. Fabrication of the CuxFe3-x(HHTP)2-based immunosensor · Scheme 1
Other	phosphate buffered saline (PBS)	0.01 M, pH 7.4	p.3 · 2.2. Fabrication of the CuxFe3-x(HHTP)2-based immunosensor · Scheme 1
Other	graphene/MWCNTs nanocomposite ink	small amount printed at pre-designed location	p.3 · 2.2. Fabrication of the CuxFe3-x(HHTP)2-based immunosensor · Scheme 1
Other	Ag/AgCl paste ink	printed as reference electrode	p.3 · 2.2. Fabrication of the CuxFe3-x(HHTP)2-based immunosensor · Scheme 1

Complete recipeSource: Both

Route 3: Drop Cast

p.3 · 2.2. Fabrication of the CuxFe3-x(HHTP)2-based immunosensor

SolventsMilli-Q water for MOF suspension; PBS for washing; piranha solution, ethanol, water and 0.5 M H2SO4 used for AE pre-treatment

AdditivesAntibody and BSA used for immunosensor construction states; 0.05 um alumina slurry for polishing

Atmospheredried under nitrogen after AE pre-treatment

Substrate orientationBare gold electrode (AE) replacing SPE

Work-upAE polished with 0.05 um alumina, sonicated in 3:1 H2SO4/H2O2 piranha solution, ethanol and water for 15 min each, electrochemically washed from -0.2 to 1.6 V in 0.5 M H2SO4, rinsed with ultrapure water, dried under nitrogen, then modified in the same way as SPE.

Activationnot reported

Show 4 structured reagent records

Role	Reagent	Amount / concentration	Source
Other	CuxFe3-x(HHTP)2 suspension	Not specified	p.3 · 2.2. Fabrication of the CuxFe3-x(HHTP)2-based immunosensor
Other	bare gold electrode (AE)	Not specified	p.3 · 2.2. Fabrication of the CuxFe3-x(HHTP)2-based immunosensor
Acid	piranha solution (H2SO4/H2O2)	sonicated for 15 min · v/v 3:1	p.3 · 2.2. Fabrication of the CuxFe3-x(HHTP)2-based immunosensor
Electrolyte	H2SO4	oxidation/reduction cycling from -0.2 to 1.6 V · 0.5 M	p.3 · 2.2. Fabrication of the CuxFe3-x(HHTP)2-based immunosensor

Complete recipeSource: Both

Route 4: Solvothermal

p.3 · 2.1. Synthesis of CuxFe3-x(HHTP)2 · Scheme 1

Metal precursors(CH3COO)2-Cu.2H2O, 19.97 mg (0.1 mmol); (CH3COO)2Fe, 17.39 mg (0.1 mmol)

Linker precursorsHHTP, 32.43 mg (0.1 mmol)

SolventsN,N-dimethylformamide (3.5 mL) and deionized water (3.5 mL)

Atmospherenot reported

Temperature90

Time24

Work-upUltrasonication and stirring for 1 h before autoclaving; product collected by centrifugation, washed with ethanol three times and vacuum dried at 60 C overnight.

Activationnot reported beyond vacuum drying at 60 C overnight

Scalability contextBatch autoclave synthesis at 90 C; no yield or scale-up discussion reported.

Show 5 structured reagent records

Role	Reagent	Amount / concentration	Source
Metal Source	(CH3COO)2-Cu.2H2O	19.97 mg · 0.1 mmol	p.3 · 2.1. Synthesis of CuxFe3-x(HHTP)2 · Scheme 1
Metal Source	(CH3COO)2Fe	17.39 mg · 0.1 mmol	p.3 · 2.1. Synthesis of CuxFe3-x(HHTP)2 · Scheme 1
Linker	HHTP	32.43 mg · 0.1 mmol	p.3 · 2.1. Synthesis of CuxFe3-x(HHTP)2 · Scheme 1
Solvent	N,N-dimethylformamide	3.5 mL	p.3 · 2.1. Synthesis of CuxFe3-x(HHTP)2 · Scheme 1
Solvent	deionized water	3.5 mL	p.3 · 2.1. Synthesis of CuxFe3-x(HHTP)2 · Scheme 1