Graphene-based fluorescent biosensors for detecting biomolecules, nucleic acids, biomarkers, pathogens, food toxins, metal ions and pesticides^a.

Biosensor type	Graphene-based nanocomposites	Target	Linear range	Limit of detection (LOD)	Ref.
Biomolecules	Tyramine-functionalized GQDs	Glucose	50 nM to 2 μM	7.2 nM	670
	Tyramine-functionalized GQDs	H2O2	1 nM to 150 nM	0.32 nM	670
	Tyramine-functionalized GQDs	Cholesterol	80 nM to 10 μM	1.2 nM	670
	Tyramine-functionalized GQDs	l-Lactate	200 nM to 25 μM	47 nM	670
	Tyramine-functionalized GQDs	Xanthene	100 nM to 18 μM	32 nM	670
	PVA/GQDs	Glucose	0.25–24 mM	10 μM	671
	PVA/GQDs	H2O2	0.05–35 mM	1.0 μM	671
	GLY-GQDs	Ce4+	0.03–17.0 μM	25 nM	672
Nucleic acids	GO	miRNA	0.02–100 fM	3 fM	673
	GO	miRNA	10 fM to 10 pM	3 fM	674
	rGO	Hepatitis B virus (HBV)	0.05 pg mL−1 to 1 ng mL−1	0.05 ng mL−1	675
Biomarkers	GQDs	Cardiac marker antigen troponin I (cTnI)	0.001–1000 ng mL−1	0.192 pg mL−1	676
	GR	PSA	100–500 ng mL−1	100 ng mL−1	677
Pathogens	GQDs/AuNPs	S. aureus	100 pM to 100 nM	1 nM	678
	GR magnetic nanosheets/CS	P. aeruginosa	4.5 × 102 to 5 × 102 CFU mL−1	5 CFU mL−1	679
		S. aureus		4.5 CFU mL−1
	GR sheets	Oxytetracycline	0.01–0.2 μM	0.01 μM	680
	GO/nucleic-acid stabilized Ag nanoclusters hybrid	DNA	0–1000 nM	0.5 nM	681
		ATP		2.5 nM
		Thrombin		0.5 nM
Food toxins	GO/UC NPs	Ochratoxin A (OTA)	0.05–100 ng mL−1	0.02 ng mL−1	682
		Aflatoxin B1 (AFB1)	0.1–500 ng mL−1	0.1 ng mL−1
	GO	OTA	2.0–35 μM	1.9 μM	683
	CdTe QDs/GO	AFB1	3.2 nM to 320 μM	1 nM	684
	GQDs	OTA	0.05–20 ng mL−1	13 pg mL−1	685
	GO/Au nanocomposite	AFB1	0.1–10 pg mL−1	0.03 pg mL−1	686
Metal ions	GR/DNAzymes complex	Cu2+	0–250 nM	2 nM	687
	GR/DNAzyme	Cu2+	0.01–1.5 μM	0.365 nM	688
	GR/DNAzyme	Pb2+	0.5 nM to 2 μM	0.5 nM	689
	GQDs/DNA	Hg2+	1 nM to 10 μM	0.25 nM	690
	GO/guanine-quadruplex DNA aptamer	Pb2+	0.75/6.0 nM L−1	0.40 nM L−1	691
	CdSe/ZnS QDs/GO	Pb2+	0.1–10 nM	90 pM	692
	GO	Hg2+	1–50 nM	0.92 nM	693
	GQDs	Cu2+	0–15 μM	0.226 μM	694
	GQDs/GO	Pb2+	Up to 400 nM	0.6 nM	695
	Carbon dots/ODN/GO	Hg2+	5–200 nM	2.6 nM	696
	Dopamine/GQDs	Fe3−	20 nM to 2 μM	7.6 nM	697
	GO-AuNPs	Pb2+	2 nM to 0.23 μM	0.1 nM	698
	Macroporous GR foam	Pb2+	50–500 pM	50 pM	699
		Cu2+		0.6 nM
	GQDs	Fe3−	0 to 60 μM	0.45 μM	700
	Pi-A/rGO	Cu2+	5–300 μg mL−1	0.67 μg mL−1	591
	N-doped GQDs	Al3+	2.5–75 μM	1.3 μM	701
	S-doped GQDs	Ag+	0.1–130 μM	30 nM	702
	GQDs	Cu2+	0.1–1 μM	0.067 μM	703
	GQDs/AuNPs	Pb2+	50 nM to 4 μM	16.7 nM	704
	N-doped GQDs	Hg2+	2–200 nM	0.32 nM	705
Pesticides	N-doped GQDs	Omethoate	0.1–1.7 nM	0.041 pM	706
	N-doped GQDs MIP	Thiacloprid	0.1–10 mg L−1	0.03 mg L−1	707

^aAbbreviations used PVA: poly(vinyl alcohol), PSA: (prostate specific antigen, a cancer marker), GLY: glycine, AFB1: aflatoxin B1, cTnI: cardiac marker antigen troponin I in blood, ATP: adenosine triphosphate, Pi-A: N-(2-(1-(p-tolyl)-1H-phenanthro[9,10-d]imidazol-2-yl)phenyl)picolinamide, CDs: carbon dots, ODN: oligodeoxyribonucleotide, MIP: molecularly imprinted polymer. Upconversion fluorescent NPs: BaY_0.78F₅:Yb_0.2,Er_0.02 and BaY_0.78F₅:Yb_0.7,Tm_0.02 nanoparticles.