Electronic supporting information

Sensitive and highly selective determination of vitamin B1 in the presence of

other vitamin B complexes using functionalized gold nanoparticles as

fluorophore

Sekar Shankar and S. Abraham John*

Center for Nanoscience and NanotechnologyDepartment of Chemistry, Gandhigram Rural InstituteGandhigram – 624 302, Dindigul, Tamilnadu, India.

Electronic Supplementary Material (ESI) for RSC Advances.This journal is © The Royal Society of Chemistry 2015

OHS

NN

N

NH2

Thiamine Hydrochloride (Vitamin B1)

+

Cl-A N

NHS

OH

NH2

4-amino-6-hydroxy-2-mercapto pyrimidine (AHMP)

BA

N

HNN

NO

O

HO

OHHO

HO

Vitamin B2

CDBA

N

O

HO

Vitamin B3

DN

HO

OH

OH

Vitamin B6

E

O

HO

O

HO

O

HN

HN

N

N

N

N

OH

H2N

Vitamin B9

FBA

OO

HO

OH

OHHO

Vitamin C

G

Chart S1. Structures of AHMP and vitamin B complexes.

200 400 600 800

0

1

2

Abso

rban

ce

Wavelength (nm)

ab

c d

Fig. S1. Absorption spectra obtained for (a) AHMP, (b) HAuCl4 and after the addition (c) HAuCl4

to AHMP and (d) NaBH4 to a mixture of HAuCl4 and AHMP. Inset: Photograph of synthesized

AHMP-AuNPs .

Fig. S2. UV-visible (A) and emission spectra (B) of AHMP-AuNPs (λex: 520 nm; λem: 781 nm).

ABA

400 600 800

0

1

Abs

orba

nce

Wavelength (nm)

BA

760 780 8000

100

200

Inte

nsit

y

Wavelength (nm)

Fig. S3. UV-visible spectra of AHMP-AuNPs (a) freshly prepared, (b) after the three month. Inset:

Corresponding photographs of UV-visible spectra (a) freshly prepared, (b) after the five month.

400 600 800

0.5

1

Abs

orba

nce

Wavelength (nm)

b

a ba

A BA

.

Fig. S4. Zeta potential measurement of AHMP-AuNPs (A) before and (B) after the addition of

1.20 × 10-6 M thiamine.

40 60 802

Inte

nsity

(a.u

)

(111

)(2

00)

(220

) (311

)

Fig. S5. X-ray Diffraction pattern of AHMP-AuNPs.

400 600 800

0

1

a

m

Abs

orba

nce

Wavelength (nm)

Fig. S6. UV-vis spectra of AHMP-AuNPs in different concentrations of thiamine: (a) 0, (b)

0.15, (c) 0.30, (d) 0.45, (e) 0.60, (f) 0.75, (g) 0.90, (h) 1.05, (i) 1.20 , (j) 1.35, (k) 1.50, (l)

1.65 and (m) 1.80 × 10-6 M.

760 780 8000

100

200FL

inte

nsity

Wavelength (nm)

450

520 nm

600 nm

525

exci

tatio

n (e

x)

ex

Fig. S7. Emission spectra of AHMP-AuNPs by varying excitation wavelength from 450 -

600 nm (interval 5 nm).

-11.0 -10.8 -10.6 -10.4 -10.2 -10.0 -9.8

-1.0

-0.8

-0.6

-0.4

-0.2R2=0.9949y=7.7802+0.8034x

log

[F-F

0/F0]

log [Q]

Fig. S8. Plot for binding constant of AHMP-AuNPs with thiamine.

Table S1. DFT calculation of AHMP and AHMP-AuNPs

Compound HOMO LUMO

Energy

gap (eV)

AHMP 4.8731

AHMP-

AuNPs2.4990

Table S2. Comparison of thiamine limit of detection and linear range obtained in the present work

with reported methods

Methods Medium Linear rangeLimit of

detectionRef.

Spectrofluorimetry alkaline 1×10-4 - 1×10-8 M 4.3 nM L-1 2

Spectrofluorimetry water 3.3 µM – 8.3 nM 2.6 nM L-1 14

Spectrofluorimetry alkaline1.9×10-4 – 2.7×10-7

M5×10-8 M L-1 15

HPLC methonal5×10-7 M - 5×10-10

M1×10-10 M L-1 20

Capillary

electrophoresiswater Not reported 0.05 µg ml-1 23

Square wave

voltammetrywater 2.2 µM - 1×10-8 M 5.5 nM L-1 24

Chemiluminescence water 4×10-5 - 1×10-7 M 4.8 nM L-1 43

Spectrofluorimetry water 10 – 120 pM 6.8 fM L-1 present method

Table S3. Determination of thiamine in human blood serum samples (n=5)*

Samples thiamine spiked (ng L-1) thiamine found (ng L-1) RSD Recovery (%)

Sample 1 10 9.9 ± 0.1 0.55 99.4

Sample 2 20 19.9 ± 0.1 0.42 99.6

* Five replicate measurements