Alternative electrodes in electroanalysis

LABORATÓRIO DE ANALÍTICA•BIOANALÍTICA•BIOSSENSORES•ELETROANALÍTICA &•SENSORES

DQUFSCar

Orlando Fatibello-Filho

LABBES / Departamento de Química Universidade Federal de São Carlos (UFSCar)

bello@ufscar.br; www.ufscar.br/labbes

3

São Carlos

DEPARTMENT OF CHEMISTRY

7

LABBES

POTENTIOMETRICS

AMPEROMETRICS /VOLTAMMETRICS

PIEZOELECTRICS

PVC electrodes

Metal-metal Oxide electrodesBiosensors

Composites electrodes

Amalgam electrodes

Bismuth film electrodes

Carbon nanotubes, carbon paste and carbon composite electrodes

Boron-doped diamond (BDD) electrode

Amorphous carbon nitride (a-CNx) electrode

Biosensors

Advantages

Determination of analyte in colored solutions and/or with material in suspension

In situ determination of analyte: portability of the instrument

Simultaneous determination of inorganic and/or organic analytes

Speciation of analyte

Disadvantages

Adsorption of substances in the electrode surface

Low stability of work electrodelow reproducibility

Introduction: Electroanalytical Methods

Electrolysis with a Dropping Mercury Cathode

Heyrovský`s article (1922)

J. Heyrovský, Chimické Listy, 16, 256 (1922)

Polarography

Fig. J. Heyrovsky, Masuzo Shikata and the apparatus for measuring current-voltage curves in electrolysis with dropping mercury electrode (DME) and a sensitive photographic paper)

J. Heyrovský, M. Shikata, Rec. Trav. Chim. Pays-Bas, 44, 496 (1925)

Fig. (A) Polarograph, (B) December 10th, 1959 received from the hands of King of Sweden Gustav Adolph VI Nobel Prize for his invention of polarography and (C) Nobel Prize Certificate

(A)

(B)

(C)

Characteristics of the dropping-mercury electrode (DME)Advantages

High hydrogen overpotential

Good stability

Good reproducibility

Characteristics of noble metals (Au, Pt)

Disadvantages

O2 should be removed from solutions

Flow analysis

Use is limited in positive potentials

Toxicity

ISE 2010Nice, France

Clarkson University, Potsdam, NY

Alternative electrodes in electroanalysis

Alternative electrodes in electroanalysis

Amalgam Electrodes for Electroanalysis

Fig. Dental and/or Amalgam Electrode

E. Mikkelsen, K.N. Schroder, Electroanalysis, 15(8), 679 (2003)B. Yosypchuc, J. Barek, Crit. Rev. Anal. Chem., 39, 189 (2009)D. de Souza, L. H. Mascaro, O. Fatibello-Filho, J. State. Electrochem., 15, 2023 (2011)D. de Souza, L.C. Melo, A.N. Correa, P. Lima-Neto, O. Fatibello-Filho, L. H. Mascaro, Quim. Nova, 34(3), 487 (2011)C. M. A. Brett, F. Trandafir, J. Electroanal. Chem., 572(2), 347 (2004).

Classification of amalgam electrodes

Approximate potential ranges for platinum, mercury, carbon, boron-doped diamond (BDD), amorphous carbon nitride (a-CNx) and bismuth electrodes

3.0 vs SCE-3.00

1M H2SO4

1M NaOHPt

1M NaOH

1M H2SO4

1M KCl Hg

1M HClO4

0.1 M KCl C

0.5 M H2SO4 BDD

1M HClO4 0.5 M NaOH

Bi

0.5 M H2SO4 a-CNx

• Good negative potential window

• Interference of dissolved oxygen is minimal

• Low toxicity

• Electrochemical behavior is similar to that of mercury

Bismuth film electrodes

L.C.S. Figueiredo-Filho, D.C. Azzi, B.C. Janegitz, O. Fatibello-Filho, Electroanalysis, 24(2), 303 (2012)L.C.S. Figueiredo-Filho, B.C. Janegitz, R.C. Faria, O. Fatibello-Filho, L. H. Marcolino-Jr, F.R. Caetano, I.L de Mattos, Quim. Nova, 35(5), 1016 (2012)L.C.S. Figueiredo-Filho, V.B. dos Santos, T.B. Guerreiro, O. Fatibello-Filho,R.C. Faria, L.H. Marcolino-Jr, Electroanalysis, 22(11), 1260 (2010)A. Caldeira, C. Gouveia-Caridade, R. Pauliukaite, Brett, C. M. A., Electroanalysis, 23(6), 1301 (2011)

= =Copper

plate3-electrodes

schemeInsulating

film

Definitionof the

superficial area

Agdeposit

Bideposit

Bi Filmmini-sensor

= =Copper

plate3-electrodes

schemeInsulating

film

Definitionof the

superficial area

Agdeposit

Bideposit

Bi Filmmini-sensor

Bismuth film electrode for in situ determinations

A B

C

(A): PalmSens and (B): DropSens potentiostats and (C) BiSPE preparation

L. C. S. Figueiredo-Filho et al., Analytical Methods, 5, 202 (2013)

TT-type connector for printers

Fig. A) electrochemical cell built with inexpensive materials and B) set for analysis: connector, minisensor and electrochemical cell (ink color container) for in situ determinations

Bismuth film electrode for in situ determinations

L.C.S. Figueiredo-Filho, B.C. Janegitz, R.C. Faria, O. Fatibello-Filho, L. H. Marcolino-Jr, F.R. Caetano, I.L. de Mattos, Quim. Nova, 35(5), 1016 (2012)

A B C

Fig. FEG-SEM (Field emission gun scanning electron microscope) micrographs of the bismuth film electrodeposited onto a copper electrode: A) copper substrate, B) BiFE 15000 X and C) XRD (X-ray Diffraction): Bi black and Cu (gray)

Bismuth film -0.18 V vs. Ag/AgCl (3.0 mol L-1 KCl) during 200 s 0.02 mol L-1 Bi(NO3)3, 1.0 mol L-1 HCl in 0.15 mol L-1 sodium citrate

Bismuth film electrode for in situ determinations

Bismuth film electrode (BiFE) for paraquat determination

Fig. DP voltammograms of paraquat (1,1'-dimethyl-4,4'-bipyridinium dichloride) in 0.1 mol L-1 acetate buffer solution (pH 4.5)

L.C.S. Figueiredo-Filho, V.B. dos Santos, B.C. Janegitz, T.B. Guerreiro, O. Fatibello-Filho, R.C. Faria, L.H. Marcolino-Jr, Electroanalysis, 22(11), 1260 (2010)

NH3C N CH3e H3C CH3-

N N

H3C CH3e-

H3C N CH3N N N

E2 = -0.98 V vs. (Ag/AgCl) PQ2

E1 = -0.67 V vs. (Ag/AgCl) PQ1

(PQ2+) (PQ +)

(PQ +) (PQº)

Bismuth film electrode (BiFE) for atrazine determination

Fig. Proposed mechanism for reduction of 2-chloro-4-(ethylamine)-6-(isopropylamine)-s-triazine (ATZ)

L.C.S. Figueiredo, D.C. Azzi, B.C. Janegitz, O. Fatibello-Filho, Electroanalysis, 24, 303 (2012)

Pb2+: 1.3 – 13.0 µmol L-1 , LD: 0.83 µmol L-1

Cd2+: 0.99 – 12 µmol L-1 , LD: 0.53 µmol L-1

Instrumentação portátil (bateria), robusta, exata e precisa

Análises rápidas Controle térmico

Uso de ferramentas de tecnologia da informação (TI): Comunicação Wi-Fi, Bluetooth, GPS, GSM, telefonia 3G (SMS).

Rede Wi-Fi

Determinação in situ e on-line analitos orgânicos e cátions metálicos

GPS-0,7 -0,6 -0,5 -0,4 -0,3 -0,2

0

100

200

300

400

500

600

700

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

0

100

200

300

400

500

600

I / A

[Pb2+] / 10-6 mol L-1

I / A

E / V Vs Ag

Potentiostat

Fig. Structures of (a) glassy carbon, (b) graphite, (c) carbon nanotubes, (d) graphite powder, (e) carbon fibres, (f) boron-doped diamond, (g) fullerene (h) graphene and (i) pyrolitic graphite (not shown)E.T.G. Cavalheiro, C.M;.A. Brett,, A. M. Oliveira-Brett, O. Fatibello-Filho, Bioanal. Rev, 4, 31 (2012); Pauliukaite, R., Ghica, M.E., Brett, C.M.A., Fatibello-Filho, O., Anal. Chem., 81, 5164 (2009); Ghica, M.E., Pauliukaite, R., Brett, C.M.A., Fatibello-Filho, O., Sensors and Actuactors, 142, 308 (2009)

(g)

Carbon, carbon paste and carbon composite electrodes

Schematics of an individual (A) SWCNT and (B) MWCNT

A: 1-2 nm diameter B: 2 to 100 nm separated by a distance of 0.3-0.4 nm

Single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs)

Iijima, S., Nature, 354, 56 (1991); Merkoçi, A. et al. Trend Anal. Chem., 24, 826 (2005)

Carbon nanotubes

Good electrical conductivity and mechanical strength

Relatively chemically inert in most electrolyte solutions

High surface activity

Wide operational potential window

Insolubility of CNTs in all solvents

Wildgoose, G. G. et. al. Microchim. Acta, 152, 187 (2006); Banks, C. E. et al. Chem. Commun., 829-841 (2005); Merkoçi, A. et al. Trend Anal. Chem., 24, 826 (2005).

Treatment of carbon nanotubes

Treatment of the carbon nanotubes increases the sensitivity of the electrodes, because there is the appearance of reactive groups such as -COO-,-OH, C=O and others

The literature reports several treatments, which use mainly concentrated 2 mol/L HCl, H2O and conc. H2SO4/ HNO3 3:1 v/v

B.C. Janegitz, L.H. Marcolino-Junior, S.P. Campana-Filho, R.C. Faria, O. Fatibello-Filho, Sens. Actuators B-Chem., 142, 260 (2009)H.H. Takeda, B.C. Janegitz, R.A. Medeiros, L.H.C. Mattoso, O. Fatibello-Filho, Sens. Actuators B-Chem., 161, 755 (2012)

Fig. Cyclic voltammograms (50 mV s−1), after background subtraction, of a (a) GCE and (b) MWCNTs-PAH/GCE for 250 µM AA and a 450 µM sulfite in 0.1 M acetate buffer solution (pH 4.6).

Simultaneous Voltammetric Determination of Ascorbic Acid and Sulfite in Beverages Employing a Glassy Carbon Electrode Modified with Carbon Nanotubes within a Poly(Allylamine Hydrochloride) (PAH) Film

E.R. Sartori, O. Fatibello-Filho, Electroanalysis, 24(3), 627 (2012).

(PAH)

OO

OH

NH3HO

OO

HO NH3

OH

OO

OH

NH2HO

OO

HO NH2

OH

n

+ 2n H+

Soluble

Insoluble

Chemical equilibrium of chitosan in solution

Chitosan (linear -1,4-linked polysaccharide)

Pauliukaite, R. ; Ghica, M. E. ; Fatibello-Filho, O. ; Brett C.M.A., Anal. Chem., 81, 5364-5372 (2009)

Pauliukaite, R. ; Ghica, M. E. ; Fatibello-Filho, O. ; Brett C.M.A. Electrochimica Acta, 55, 6239 (2010)

NC

N N

1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDCEDC)

HO

O

O

N

N-hydroxysuccinimide (NHSNHS)

EDC-NHS

Possible mechanism of covalent binding of CNTs using Chit crosslinking and EDC/NHS (1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-

hydroxysuccinimide)Pauliukaite, R., Ghica, M.E., Brett, C.M.A., Fatibello-Filho, O., Anal. Chem., 81, 5164 (2009)

Ghica, M.E., Pauliukaite, R., Brett, C.M.A., Fatibello-Filho, O., Sensors and Actuactors, 142, 308 (2009)

CO H

N

OC

O O

OO

O

NHHO

OO

HO NH

O

OH

C

OO

O

OH

NHHO

OO

HO N

OH

HN

C

O O

N

A

B

Scheme of possible ways of enzyme immobilization at the electrode modified with chitosan and MWCNTs: (A) enzyme attachment directly to CNTs by EDC-NHS and (B) enzyme linked to both chitosan and to CNTs by EDC-NHS and GA.

HO

O

O

NnC

O OH

C

OHO

NH

C

N

N

OC

OC

O

O

O

O

N

C

O OH

C

O

NH

C

O OH

C

O

NH

C

O OH

Carbon paste electrodes

C. Vieira, O. Fatibello-Filho, Talanta, 52(4), 681 (2000)M. F. S. Teixeira, A. Z. Pinto, O. Fatibello-Filho, Talanta, 45(2), 249 (1997)B. C. Janegitz, L. C. S. Figueiredo-Filho, L. H. Marcolino-Jr, O. Fatibello-Filho, J. Electroanal. Chemistry, 660(1), 209 (2011)F. C. Vicentini, L.C.S. Figueiredo-Filho, B. C. Janegitz, A. Santiago, E.R. Pereira, O. Fatibello-Filho, Quim. Nova, 34(5), 825 (2011)

T. Navratil, J. Barek, Crit. Rev. Anal. Chem., 39, 131 (2009)

Composite Electrodes

Fig. Composite Electrode

C. M. F. Calixto, P. Cervini, E. T. G. Cavalheiro, Quim. Nova, 31(8), 2194 (2008)

I. Cesarino, C. Gouveia-Caridade, R. Pauliukeite, E. T. G. Cavalheiro, Brett, C. M. A., Electroanalysis, 22(12), 1437 (2010)

I. Cesarino, E. T. G. Cavalheiro, Brett, C. M. A., Microchimica Acta, 171 (1-2), 1 2010)

Composite electrode

Boron-doped diamond electrode

corrosion stable in very aggressive media

very low and stable background current

very low adsorption of organic/inorganic species

extreme electrochemical stability in both alkaline

and acid media

high response sensitivity

very wide working potential window (3.5 V)K. Pecková et al. Critical Reviews in Analytical Chemistry. 39 (2009) 148

L.S. Andrade, G. R. Salazar-Banda, R. C. Rocha-Filho, O. Fatibello-Filho, Cathodic Pretreatment of Boron-Doped Diamond Electrodes and Their Use in Electroanalysis, In: Synthetic Diamond Films: Preparation, Electrochemistry, Characterization, and Applications, (Eds. E. Brillas and C. A. Martínez-Huitle), John Wiley & Sons, Inc., Hoboken, NJ, USA, 2011.

Experimental

Working electrode: Boron-doped diamond film (8000 ppm) on a silicon wafer from Centre Suisse de Electronique et de Microtechnique SA (CSEM), Neuchatêl, Switzerland

Cathodic pretreatment: –1.0 A cm–2 for 180 s in a 0.5 M H2SO4 solution

Anodic pretreatment: +1.0 A cm-2 for 180 s in a 0.5 M H2SO4

solution

Counter electrode: Pt wire

Reference electrode: Ag/AgCl (3.0 M KCl)

Potentiostat/galvanostat: Autolab PGSTAT-30 (Ecochemie) controlled with the GPES 4.0 software

Electrochemical pre-treatments

Characteristics of the procedure: simple and rapid low cost good intra- and inter-day repeatabilities

Electrochemical pre-treatments

Cathodic pre-treatment

Hydrogen-terminated BDD(HT-BDD)

Anodic pre-treatment

G.R. Salazar-Banda, L.S. Andrade, P.A.P. Nascente, P.S. Pizani, R.C. Rocha-Filho, L.A. Avaca. Electrochimica Acta, 51, 4612 (2006)

Oxygen-terminated BDD(OT-BDD)

Square-wave voltammetric determination of acetylsalicylic acid in pharmaceutical formulations using a BDD electrode without the need of previous alkaline hydrolysis step

E.R. Sartori, R.A. Medeiros, R.C. Rocha-Filho, O. Fatibello-Filho. J. Braz. Chem. Soc., 20 360 (2009); T.A. Enache, O. Fatibello-Filho, A. M. Oliveira-Brett. Combinatorial Chemistry & High Throughput Screening, 13, 569 (2010)

HTB: 2-(hydroxyl)-4-(trifluoromethyl)-benzoic acid LOD = 2.0 M

Highlight:first voltammetric

method in the literature!

Paracetamol (A) and caffeine (B) in pharmaceuticals

B.C. Lourenção, R.A. Medeiros, R.C. Rocha-Filho, L.H. Mazo, O. Fatibello-Filho,Talanta, 78, 748 (2009)

Differential pulse voltammetryParacetamol: 0.50 – 83 M LOD = 0.049 MCaffeine: 0.50 – 83 M LOD = 0.035 M

Highlight:LODs lower than those reported; higher sensitivity and larger linear concentration range of the analytical curve

17 M

38 M

0.4 0.6 0.8 1.0 1.2 1.4 1.6

101520253035404550

I/A

E/V vs Ag/AgCl 0.4 0.6 0.8 1.0 1.2 1.4 1.6

0

10

20

30

40

50

60

70

I/A

E/V vs Ag/AgCl

Repeatability study for 0.029 M Ascorbic acid + 0.79 M caffeine in 0.1 M H2SO4 (n = 10)

RSD = 8.7 % for glassy-carbon (GC) electrodeRSD = 1.0 % for boron-doped diamond (BDD) electrode

Repeatability study

GC BDD

Highlight:higher repeatability of the BDD

electrode

B.C. Lourenção; R.A. Medeiros; R.C. Rocha-Filho; O. Fatibello-Filho; Electroanalysis, 22, 1717 (2010)

Simultaneous voltammetric determination of synthetic colorants in food using a cathodically pretreated BDD electrode

R. A. Medeiros, B.C. Lourenção, R. C. Rocha-Filho, O. Fatibello-Filho, Talanta, 97, 291 (2012); R. A. Medeiros, B.C. Lourenção, R. C. Rocha-Filho, O. Fatibello-Filho, Talanta, 99, 883 (2012)

TT/SYTT

TT/SYSY

BB BB/SY BB/SY

LOD = 62.7, 13.1 and 143 nmol L-1 for TT, SY and BB, respectively.

Fig. Chemical structures of the Tartrazine (TT), Sunset yellow (SY) and Brilliant blue (BB) and DP voltammograms

Simultaneous Square-Wave Voltammetric Determination of Phenolic Antioxidants (BHA and BHT) in Food Using a Boron-Doped Diamond Electrode

R.A. Medeiros, R.C. Rocha-Filho, O. Fatibello-Filho, Food Chemistry, 123 , 886 (2010)

BHA = butylated hydroxyanisole; BHT = butylated hydroxytoluene

OCH3

OH

C(CH3)3

H2O

O

O

C(CH3)3

CH3OH H3O+

BHA

H2O(CH3)3C C(CH3)3

O

CH3

H3O+ 2 e-

OCH3

C(CH3)3

O

H3O+ 2 e- 2H2O

+

BHT

(CH3)3C C(CH3)3

OH

CH3

BHA: 0.60 – 10 M; LOD = 0.14 M

BHT: 0.60 – 10 M; LOD = 0.25 M

BHA

BHT

Highlight:LODs lower than those

previously reported

OCH3

OH

C(CH3)3

(CH3)3C C(CH3)3

OH

CH3

Flow Injection analysis system

Potentiostat/galvanostat: Autolab PGSTAT-30 (Ecochemie)

Flow electrochemical cell

Working electrode :BDD

8000 ppm; 0.33 cm2

Reference electrode Ag/AgCl

(3.0 mol L–1 KCl)

Counter electrode : stainless steel tube

E. M. Richter et al. Quim. Nova, 26(6), 839 (2003) L. Andrade et al. Anal. Chim. Acta 654, 127 (2009)

Flow injection simultaneous determination of BHA and BHT with multiple pulse amperometric detection at a BDD electrode

Fig. Hydrodynamic voltammograms obtained for (A) 0.10 mmol L-1 BHA and (B) 0.10 mmol L-1 BHT by use BDD; flow rate = 2.4 mL min-1

and Vsample = 250 µL

R.A. Medeiros; B.C. Lourenção; R.C. Rocha-Filho, O. Fatibello-Filho; Anal. Chem.,82, 8658 (2010)

(A) MPA waveform applied to the cathodically pretreated BDD working electrode as a function of time. (B) Flow-injection pulse amperometric responses in triplicate for solutions containing 50 μmol L-1 BHA or BHT or both analytes simultaneously at this concentration. Supporting electrolyte: aqueous ethanolic (30% ethanol, v/v) 10 mmol L-1 KNO3 solution (pHcond =1.5) adjusted with concentrated HNO3); flow rate 2.4 mL min-1; injected volume 250 μL.

FIA-MPA amperograms obtained after injections of solutions containing BHA (0.050-3.0 μmol L-1) and BHT (0.70-70 μmol L-1) simultaneously or different samples of mayonnaise (A-D). Supporting electrolyte: aqueous ethanolic (30% ethanol, v/v) 10 mmol L-1 KNO3 solution (pHcond =1.5) adjusted with concentrated HNO3); flow rate 2.4 mL min-1; injected volume 250 μL.

(A) Diagram of the multicommutated stop-flow system: V1 and V2: solenoid valves; A: sample or standard solution; C: carrier solution (BR buffer pH 7.0). (B) Transient DPV signals in triplicate for sulfamethoxazole (1.0 – 8.0 mg L–1) and trimethoprim (0.2 – 1.6 mg L–1) determination in pharmaceuticals.

Sampling

Rate = 30 h-1

Fig. (A) Schematic representation of Tyr-AuNPs/BDD biosensor fabrication process and (B) SEM image of BDD and (C) BDD/AuNPs. Electrodeposition potential = -0.4 V and electrodeposition time = 40 s.

(A)

(B) (C)

Tyr-AuNPs/BDD biosensor

B. C. Janegitz, R. A. Medeiros, R. C. Rocha-Filho, O. Fatibello-Filho, Diamond and Rel. Mater., 25, 128 (2012); J.T. Matsushima, L.C.D. Santos, A.B. Couto, M.R. Baldan, N.G. Ferreira, Quim. Nova, 35(1), 11 (2012)

-1.0 -0.5 0.0 0.5 1.0 1.5 2.0

-0.4

0.0

0.4

0.8

I (m

A)

E (V) vs. Ag/AgCl

a-CNx

Amorphous carbon nitride (a-CNx) electrode

CV voltammograms (v = 50 mV s–1) for a-CNx electrode in 0.5 mol L–1 H2SO4 supporting electrolyte.

Lagrini et al. Electrochemistry Communications 6, 245 (2004)R.A. Medeiros, R. de Matos, C. Debiemme-Chouvy, A. Pailleret, H. Cachet, C. Deslouis, R. C. Rocha-Filho, O. Fatibello-Filho, Electrochemistry Communications, 24. 61 (2012)

Fig. CV voltammograms (ν = 50 mV s–1) for 1.0 x 10–3 mol L–1 [K3Fe(CN)6] in 0.5 mol L–1 KCl using the a-CNx film as-received and after PTA and PTC.

Electrochemical pretreatment

Fig. CV voltammograms (ν = 50 mV s–1) obtained for 0.5 mmol L–1 dopamine (black) and 1.0 mmol L–1 ascorbic acid (gray) in 0.1 mol L–1 HClO4 using an a-CNx electrode anodically (A) or catodically (B) pretreated in 0.1 mol L–1 KOH

Pretreatment conditionsCurrent density: 3 mA cm–2 for PTA; 3 mA cm–2 for PTC in a 0.1 mol L–1 KOH Time: PTA: 180 s; PTC: 180 s

Dental and/or Amalgam Electrode

Alloy electrodes: Sn-Bi; Pt-Ru, Pt-Pd, Pt-Rh, Pt-Ir, Pt-Au, Pd-Au, Cu-Au...

Bismuth film electrode, Antimony film electrode

Carbon, carbon paste and carbon composite electrodes:

Glassy carbon, Graphite, Pyrolitic graphite electrodes

carbon nanotubes fullerene boron-doped diamond (BDD)

carbon fibres graphene amorphous carbon nitride (a-CNx)

Conclusions and prospectsDropping mercury electrode (DME) vs Alternative electrodes

63