Table 1.

HCR-based biosensors for foodborne pathogen detection.

Signal Transduction	Detected Pathogens and Target Type	Strategy	Linear Range	LOD	Detection Time	Food Samples	Ref.
Colorimetry	E. coli O157:H7; cell	ELISA; HRP enzyme	5 × 102–1 × 107 CFU/mL	1.08 × 102 CFU/mL in pure culture and 2.6 × 102 CFU/mL in milk	~7.5 h	Milk	[32]
	Salmonella spp. and S. aureus; DNA	G-quadruplex DNAzyme	1–1 × 105 CFU/mL	10 CFU/mL	130 min	Skim milk	[33]
	Escherichia coli; cell	Two types of mechanisms based on AuNP	1 × 102–1 × 104 CFU/mL	10 CFU/mL	~80 min	Tap water and milk	[34]
	S. aureus; mecA gene	Multi-color; AuNBPs	10–100 pM	2.71 pM	1 h	Milk	[38]
	L. monocytogenes; genomic DNA	GOx/HRP enzyme cascade; Boolean logic function	0.1–10 nM (colorimetry); 0−50 nM (electrochemistry)	1.12 nM (colorimetry); 0.04 nM (electrochemistry)	2 h	Vegetable, meat, and milk extracts	[39]
Fluorescence	S. enteritidis; invA gene	MBs; hairpin labeled FAM	7.4 × 101–7.4 × 108 CFU/mL	74 CFU/mL	~2.5 h	Lettuce	[41]
	Mycobacterium tuberculosis; IS6110 gene	MBs; hairpin labeled TAMRA; turn-off	0.01–100 nM	10 pM	~2 h	N/A	[42]
	emetic Bacillus cereus; genomic DNA	MBs; hairpin labeled FAM; flow cytometry	7.6–7.6 × 106 CFU/mL	7.6 CFU/mL in buffer and 9.2 × 102 CFU/mL in milk	~4.5 h	Milk	[43]
	S. enteritidis; invA gene	“GO fluorescence” platform; hairpin labeled FAM; turn-on	4.2 × 101–4.2 × 107 CFU/mL	4.2 × 101 CFU/mL in buffer and 4.2 × 102 CFU/mL in milk	3.5 h	Milk	[44]
	E. coli O157:H7; fliCh7 gene	“PCR-HCR” dual-signal amplification; SYBR Green I embed dsDNA	7.2 × 101–7.2 × 106 CFU/mL	7.2 × 101 CFU/mL in buffer and 7.2 × 102 CFU/mL in milk	~3.5 h	Milk	[46]
	S. aureus; DNA	“HCR-3WJ-NEASA” circuit dual-signal amplification; CQ	10 pM–10 nM	6.7 pM	0.5 h	Milk	[47]
	S. aureus; 16S rRNA	“FAM-SYBR Green I” cooperative effect; “GO fluorescence” platform	50 pM–100 nM	50 pM	~1.5 h	Milk	[48]
	MRSA; agrA gene transcription (its mRNA)	“FAM-SYBR Green I” cooperative effect; “GO fluorescence” platform; strand-displacement polymerization reaction (SDPR)	10 fM–100 pM	10 fM	~1 h	N/A	[49]
	MRSA; agrC gene transcription (its mRNA)	“FAM-SYBR Green I” cooperative effect; “GO fluorescence” platform; Nb.BbvcI-assisted target recycling amplification (NATR)	10 fM–100 pM	7.5 fM	50 min	N/A	[50]
	Vibrio Parahaemolyticus; gyrB gene	FRET; four-way branch migration HCR circuits	0.2–60 nM	0.067 nM	90 min	N/A	[51]
	S. Typhimurium; cell	FRET; ratio fluorescence; CRISPR-Cas12a system and TDN-hHCR	10–108 CFU/mL	8 CFU/mL	~2.5 h	Milk and egg white	[53]
	E. coli O157:H7; cell	FRET; ratio fluorescence; CQ	4.9 × 101–4.9 × 106 CFU/mL	3.5 × 101 CFU/mL	~3 h	Milk	[54]
	S. aureus; cell	IFE; UCNPs; g-C3N4 NSs	10–106 CFU/mL	1 CFU/mL	3 h	Tap water and milk	[57]
Electrochemistry	S. aureus; cell	pMB NPs; DHCR	10–108 CFU/mL	1 CFU/mL	~3 h	Milk and pear juice	[69]
	E. coli O157:H7; cell	Fc-Dox; multiple amplification through the 3D DNA walker, RCA, and HCR	10–104 CFU/mL	7 CFU/mL	~2 h	N/A	[70]
	S. aureus; 16S rRNA	Silver wire across electrodes; hairpin labeled AuNPs	50–107 CFU/mL	50 CFU/mL	100 min	Milk	[71]
	S. Typhimurium;cell	CRISPR-Cas12a; electrode surface modification of electrical response reporting probes	104–108 CFU/mL	20 CFU/mL	~2.5 h	Milk	[72]
	Clostridium Perfringens; DNA	DNA-Walker; methylene blue; dual-mode output	1–108 CFU/g	1 CFU/g	N/A	Chicken, beef, duck, mutton, and pork	[78]
Surface-enhanced Raman scattering	S. aureus; cell	Au@Ag/4-ATP; PDMS-based SERS platform	28–2.8 × 106 CFU/mL	0.25 CFU/mL	2.5 h	Milk	[80]
	S. Typhimurium; cell	AgNP/DAPI; competitive indirect strategies	10–105 CFU/mL	6 CFU/mL	3.5 h	Milk	[81]
	S. Typhimurium; cell	4-NTP/AuNPs; G-quadruplex DNAzyme	5–105 CFU/mL	4 CFU/mL	105 min	Milk and tap water	[82]
POC test	S. enteritidis; DNA	Lateral flow; Sandwich structure	2.5 pM–500 nM	1.76 pM	~25 min	N/A	[83]
	S. enteritidis; 16S rRNA	Lateral flow; “initiators-on-a-string”complex	102–104 CFU/mL	53.65 CFU/mL	~40 min	Milk	[84]
	E. coli O157:H7; 16S rRNA	Lateral flow; ISD	102–105 CFU/mL	102 CFU/mL	~1.5 h	Milk	[85]
	Vibrio parahaemolyticus; cell	Lateral flow; MBs; sandwich structure	103–108 CFU/mL	2.6 × 103 CFU/mL	67 min	Shrimp	[92]
	E. coli O157:H7; cell	Microfluidic chip; PtNPs	5 × 102–5 × 107 CFU/mL	250 CFU/mL in buffer and 400 CFU/mL in milk	75 min	Milk	[95]
	S. aureus; S. enteritidis	Microfluidic chip; multi-mode analysis	3.6 × 101–3.6 × 106 CFU/mL	4 and 8 CFU/mL, respectively	15 min	Nonfat milk powder and raw ground pork	[96]
	E. coli O157:H7; cell	Pregnancy test strips and MOF; sandwich structure	103–107 CFU/mL	530 CFU/mL	86 min	Milk	[93]
	S. aureus; cell	Personal glucose meter; the invertase catalyzes sucrose into glucose	3–3 × 103 CFU/mL	2 CFU/mL	4.5 h	Peach juice, milk, and water samples	[94]
Others
Surface plasmon resonance (SPR)	S. aureus, Klebsiella pneumoniae and Escherichia coli; DNA	MNAzyme	1 × 102–1 × 106 CFU/mL	67 CFU/mL of S. aureus, 57 CFU/mL of K. pneumonia and 61 CFU/mL of E. coli	4 h	N/A	[97]
Chemiluminescence (CL)	L. monocytogenes; hlyA gene	Cloth-based microfluidics; G-quadruplex DNAzyme	2 × 10−3–2 × 106 pM	1.1 fM	80 min	Milk	[98]
Electrochemiluminescence (ECL)	E. coli O157:H7; genomic DNA	Cloth-based microfluidics; Ru(bpy)32+	102–107 CFU/mL	38 CFU/mL	~100 min	Milk	[99]

Note: N/A means not available.