A facile and sensitive peptide-modulating graphene oxide nanoribbon catalytic nanoplasmon analytical platform for human chorionic gonadotropin

Figures & data

Figure 1 Scheme of peptide-controlling GONR catalytic reaction–RRS detection of hCG.

Abbreviations: Abs, absorption; AuNP, gold nanoparticle; au, atomic unit; GONR, graphene oxide nanoribbon; hCG, human chorionic gonadotropin; RRS, resonance Rayleigh scattering.

Figure 2 RRS spectra of the GONR systems.

Notes: (A) HP–hCG–GONR–HAuCl₄–TCA system – a: 35 nmoL/L HP +240 ng/mL GONR +0.167 mmoL/L HCl +0.34 mmoL/L TCA +5.6 μmoL/L HAuCl₄; b: a+0.33 ng/mL hCG; c: a+1 ng/mL hCG; d: a+2 ng/mL hCG; e: a+4 ng/mL hCG; f: a+6 ng/mL hCG; g: a+10 ng/mL hCG; and h: a+13.33 ng/mL hCG. The inset graph was the working curve. (B) GONR–HAuCl₄–TCA system – a: 0.167 mmoL/L HCl +0.34 mmoL/L TCA+ 5.6 μmoL/L HAuCl₄; b: a+16 ng/mL GONR; c: a+40 ng/mL GONR; d: a+80 ng/mL GONR; e: a+120 ng/mL GONR; f: a+160 ng/mL GONR; g: a+240 ng/mL GONR; and h: a+320 ng/mL GONR. (C) HP–GONR–HAuCl₄–TCA system – a: 240 ng/mL GONR +0.167 mmoL/L HCl +0.34 mmoL/L TCA +5.6 μmoL/L HAuCl₄; b: a+1.4 nmoL/L HP; c: a+3.5 nmoL/L HP; d: a+7 nmoL/L HP; e: a+10.5 nmoL/L HP; f: a+14 nmoL/L HP; g: a+21 nmoL/L HP; and h: a+28 nmoL/L HP.

Abbreviations: C, concentration; I, intensity; RRS, resonance Rayleigh scattering; GONR, graphene oxide nanoribbon; HP, hCG polypeptide; hCG, human chorionic gonadotropin; TCA, trisodium citrate.

Figure 3 UV spectra of the GONR systems.

Notes: (A) HP–hCG–GONR–HAuCl₄–TCA system – a: 35 nmol/L HP +240 ng/mL GONR +0.167 mmol/L HCl +0.34 mmoL/L TCA +5.6 μmoL/L HAuCl₄; b: a+0.67 ng/mL hCG; c: a+1.67 ng/mL hCG; d: a+3.33 ng/mL hCG; e: a+6.67 ng/mL hCG; f: a+10 ng/mL hCG; and g: a+13.33 ng/mL hCG. (B) GONR–HAuCl₄–TCA system – a: 0.167 mmoL/L HCl +0.34 mmoL/L TCA +5.6 μmol/L HAuCl₄; b: a+16 ng/mL GONR; c: a+40 ng/mL GONR; d: a+80 ng/mL GONR; e: a+120 ng/mL GONR; f: a+160 ng/mL GONR; and g: a+240 ng/mL GONR. (C) HP–GONR–HAuCl₄–TCA system – a: 240 ng/mL GONR +0.167 mmoL/L HCl +0.34 mmoL/L TCA +5.6 μmoL/L HAuCl₄; b: a+5 nmoL/L HP; c: a+10 nmoL/L HP; d: a+20 nmoL/L HP; and e: a+30 nmoL/L HP.

Abbreviations: A, absorbance; UV, ultraviolet; GONR, graphene oxide nanoribbon; HP, hCG polypeptide; hCG, human chorionic gonadotropin; TCA, trisodium citrate.

Table 1 Comparison of the nanocatalysis and the inhibition of HP on the reaction of TCA–HAuCl₄

System	Linear range	Linear equation	Correlation coefficient
GONR	1.0–30 ng/mL GONR	ΔI545 nm =61.5C+203	0.9918
AuNP (d =10 nm)	1.0–25 ng/mL AuNP	ΔI545 nm =58.3C+150	0.9834
HP–GONR	2.0–30 nmoL/L HP	ΔI545 nm =47.8C+69.5	0.9804
GO	2.0–30 ng/mL GO	ΔI545 nm =36.9C−89.8	0.9621

Note: I is measured in au.

Abbreviations: HP, hCG polypeptide; TCA, trisodium citrate; GONR, graphene oxide nanoribbon; AuNP, gold nanoparticle; GO, graphene oxide; hCG, human chorionic gonadotropin; I, intensity; C, concentration; d, diameter.

Figure 4 TEMs of analysis system.

Notes: (A) 35 nmoL/L HP +240 ng/mL GONR +0.167 mmoL/L HCl +0.34 mmoL/L TCA +5.6 μmoL/L HAuCl₄. (B) A+4 ng/mL hCG. (C) A+10 ng/mL hCG.

Abbreviations: TEM, transmission electron microscopy; HP, hCG polypeptide; GONR, graphene oxide nanoribbon; TCA, trisodium citrate; hCG, human chorionic gonadotropin.

Figure 5 Effect of reagent concentration.

Notes: (A) HP −10 ng/mL hCG +240 ng/mL GONR +0.167 mmoL/L HCl +0.34 mmo/L TCA +5.6 μmoL/L HAuCl₄. (B) GONR −35 nmoL/L HP +10 ng/mL hCG +GO +0.167 mmoL/L HCl +0.34 mmoL/L TCA +5.6 μmoL/L HAuCl₄. (C) TCA – 35 nmoL/L HP +10 ng/mL hCG +240 ng/mL GONR +0.167 mmoL/L HCl +5.6 μmoL/L HAuCl₄. (D) HAuCl₄ −35 nmoL/L HP +10 ng/mL hCG +240 ng/mL GONR +0.167 mmoL/L HCl +0.34 mmoL/L TCA+HAuCl₄. (E) HCl −35 nmoL/L HP +10 ng/mL hCG +240 ng/mL GONR+HCl +0.34 mmoL/L TCA +5.6 μmoL/L HAuCl₄.

Abbreviations: HP, hCG polypeptide; hCG, human chorionic gonadotropin; GONR, graphene oxide nanoribbon; TCA, trisodium citrate; GO, graphene oxide; I, intensity; C, concentration.

Figure 6 The effect of reaction temperature and time.

Notes: (A) Reaction temperature: 35 nmoL/L HP +10 ng/mL hCG +240 ng/mL GONR +0.167 mmoL/L HCl +0.34 mmoL/L TCA +5.6 μmoL/L HAuCl₄. (B) time: 35 nmoL/L HP +10 ng/mL hCG +240 ng/mL GONR +0.167 mmoL/L HCl +0.34 mmoL/L TCA +5.6 μmoL/L HAuCl₄.

Abbreviations: HP, hCG polypeptide; hCG, human chorionic gonadotropin; GONR, graphene oxide nanoribbon; TCA, trisodium citrate; I, intensity.

Table 2 Effect of coexisting substances

Coexisting substance	Relative multiple	Relative error (%)	Coexisting substance	Relative multiple	Relative error (%)
K^+	100	−1.0	SO3^2−	100	−5.7
Ca^2+	100	−7.4	NO2^−	100	8.0
Mg^2+	100	−6.3	S2O3^2−	100	−6.0
Fe^3+	100	−5.3	CO3^2−	100	−6
IgM	10	−0.8	Glycine	100	−4
IgG	10	−3.5	Lysine	100	−7
Tryptophan	10	5.0	Aspartic acid	100	8.0
Glutamate	50	1.2	Valine	100	−4.0
Phenylalanine	50	−1.0	Tyrosine	100	−6.0

Table 3 Analysis of hCG samples

Sample	Detection value (ng/mL)	Content (ng/mL)	Added value (ng/mL)	Found value (ng/mL)	Recovery (%)	RSD (%)	Ref value (ng/mL)
1	0.548	55.6	0.25	0.7842	94.5	1.05	56.6
2	0.432	43.7	0.5	0.9258	98.8	3.97	45.7
3	0.404	40.9	1.0	1.364	90.1	1.43	39.6
4	0.480	48.6	0.5	1.010	106	0.90	46.9
5a	0.310	3.10	0.25	0.550	96.0	3.76	32.1
6	5.24	524	5.0	10.52	105.6	2.85	518
7	16.7	1,670	1.0	17.63	93.0	2.45	1,692

Note:

a The sample dilution time was 10 min.

Abbreviations: hCG, human chorionic gonadotropin; Ref, reference; RSD, relative standard deviation.