Table 1 Metal nanoparticles in periodontitis detection

Cu NPs@Cu-MOF and Ti carbide nanosheets (Ti₃C₂T_x NSs)

H₂O₂ in saliva and GCF

Versatile electrochemical platform with screen printing

Sensitivities of 254.9 μA mM⁻¹ cm⁻² (0.2–26.1 μM) and a detection limit of 84.5 nM

The concentration of H₂O₂ in saliva and GCF may serve as an indicator of the severity of periodontitis. Furthermore, it can differentiate between those who are in good health and those who have gingivitis and periodontitis by analyzing the levels of H₂O₂ in samples of saliva and GCF

[116]

Ag Nanoplates

Alkaline phosphatase (ALP) and interleukin-1beta (IL-1β)

Multicolor sensor

ALP detection range of 0–25 U/L with a limit of detection (LOD) of 0.0011 U/L, IL-1β for multicolor signaling, and it exhibits a linear detection range of 0–250 pg/mL and a LOD of 0.066 pg/mL,

The geometrical modification of an Ag nanoplate transducer is the basis for the multicolorimetric ALP and IL-1β sensing platform the researchers developed in this study

With a recovery of 100.9% in actual human saliva, the ALP multicolor sensor demonstrates excellent selectivity, demonstrating its dependability and appropriateness for easily accessible periodontal diagnostics with multivariate signal readout

[109]

AuNPs

P. gingivalis

Refractometric nanoplasmonic sensors

Less than 0.1 μg/mL (4.3 nM) well below gingipain concentrations detected in severe chronic periodontitis cases (∼50 μg/mL)

After being treated with casein or IgG, AuNPs were allowed to self-assemble as a submonolayer in multiwell plates. The breakdown of the protein coating in bacterial supernatants caused proteins in the complex sample matrix to attach to the NPs unintendedly, shifting the LSPR band by around 2 nm. Only samples exhibiting gingipain action showed a significant LSPR change

[110]

ZnO NPs with AuNPs

methyl mercaptan (CH₃SH) among volatile sulfur compounds (VSCs)

Chemiresistive gas sensors

the significant enhancement of the gas sensing performance with 4.99% gas response for 50 ppb of CH₃SH and a detection limit down to 50 ppb

The main objective is to suggest self-perceived PD sensors by strategically layering 30 nm-thick ZnO nanofilms with 3 nm-thick AuNPs using a two-step procedure, including atomic layer deposition and thermal evaporation techniques

[111]

Ag NPs

P. gingivalis

Surface-enhanced Raman spectroscopy (SERS)

LOD = 10⁵ CFU/mL, the platform can quickly identify common oral bacteria by combining with machine learning

The study included integrating advanced mechanical learning techniques with accurately categorizing four distinct oral bacteria, namely P. gingivalis, E. faecalis, S. aureus, and S. mutans. The unlabeled, user-friendly, and environmentally friendly SERS detection technique for oral bacteria has significant promise for clinical early diagnosis and prediction of disease progression in PD

[112]

Magnetic-nanobeads

Gingipains

Colorimetric assay and effective point-of-care device

It can detect as little as 49 CFU·mL⁻¹ of P. gingivalis within 30 s

The technique employs gingipains, of proteases unique to P. gingivalis, as a biomarker for detection. After the immobilized substrates were cleaved by gingipains, the magnetic-nanobeads-peptide fragments were drawn towards a magnet, causing the golden surface color to reappear. Gingipain-specific peptide substrates were used to mark magnetic nanobeads, which were then fixed on a gold biosensing platform via gold-thiol linkage

[15]

Fe₂O₃@AgNPs

P. gingivalis and A. actinomycetemcomitan

surface-enhanced Raman scattering (SERS)

LOD = 10³ cfu/mL. Additionally, the PCA performed for bacteria suspended in human saliva allowed us to separate P. gingivalis from A. actinomycetemcomitans strains with 89% accuracy

Scientists have shown that several strains of P. gingivalis and A. actinomycetemcomitans may readily adhere to Ag-coated magnetic NPs (Fe₂O₃@AgNPs). Multidisciplinary research shows that P. gingivalis may be readily detected using SERS

[113]

ZnO-PDMS

Volatile sulfur compounds (VSCs)

A transparent, wearable fluorescent mouthguard for high-sensitive visualization

The ZnO-PDMS mouthguards worn by volunteers for 7 h: fluorescence images

The ZnO-PDMS mouthguard has exceptional sensitivity and specificity in detecting VSCs while also maintaining a stable fluorescence signal. It possesses favorable biocompatibility and little toxicity when exposed to normal physiological conditions. Subsequently, the ZnO-PDMS mouthguard, which may be worn, is shown to have the capability to detect the specific positions of injury sites in individuals accurately

[114]