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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)
[email protected]; 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