Table 4 Summary of types of MXenes, their syntheses methods, surface functionalization and biomedical applications. Note: LOD indicates the lowest level of detection within the detection range stated. LOD is the lowest concentration of a substance/analyte that can be detected by a reliable analytical method, whereas the detection range includes lowest to highest concentrations of substance that are able to be detected accurately and precisely

TiO₂–Ti₃C₂

Hydrothermal synthesis

Hemoglobin (Hb), Nafion

Bio-sensor

Detection of hydrogen peroxide (LOD: 14 nM; range: 0.1–380 μM)

and nitrite (LOD: 0.12 μM; range: 0.1–380 μM) via amperometry changes

[44, 45]

Au/Ti₃C₂

HF etching

Glucose oxidase (GO_x)

Detection of hydrogen peroxide through oxidation of glucose

(LOD: 5.9 μM; range: 0.1–18 mM)

[46]

Ti₃C₂

LiF + HCl etching

Poly-L-lysine (PLL), GO_x

Detection of hydrogen peroxide through oxidation of glucose

(LOD: 2.6 μM; range: 4–20 μM, 0.02–1.1 mM)

[47]

Ti₃C₂

HF etching

Tyrosinase, chitosan

Detection of phenol in real water samples

(LOD: 12 nM; range: 0.05–15.5 μM)

[48]

Ti₃C₂

HF etching

β-hydroxybutarate dehydrogenase, bovine serum albumin (BSA), glutarate

Detection of β-hydroxybutarate

(LOD: 44.5 μM; range: 360 μM–17.91 mM)

[49]

Ti₃C₂

LiF + HCl etching

(3-Aminopropyl) triethoxysilane (APTES), BSA, anti-CEA

Detection of carcinoembryonic antigen (CEA)

(LOD: 1.8 × 10^–5 ng mL⁻¹; range: 0.0001–2000 ng mL⁻¹)

[50]

Ti₃C₂

HF etching, TMAOH intercalation

AuNPs, staphylococcal protein A, anti-CEA

Detection of CEA via surface plasmon resonance (SPR)

(LOD: 0.7 fM; range: 0.0002–20 000 pM)

[51]

Ti₃C₂

HF etching

Hollow AuNPs, APTES, SPA, anti-CEA

Detection of CEA via SPR

(LOD: 0.15 fM; range: 0.001–1000 pM)

[52]

Ti₃C₂

HF etching, DMSO intercalation

Osteopontin (OPN) aptamer, phosphomolybdic acid (PMo₁₂), polypyrrole (PPy),

Detection of overexpressed OPN

(LOD: 0.98 fg mL⁻¹; range: 0.005 pg mL⁻¹–10 ng mL⁻¹)

[53]

Ta₄C₃

HF etching

Manganese oxide (MnO_x), soybean phospholipid (SP)

Cancer theranostics

Multi-imaging-guided (MRI, CT scan and PAI) PTT

[54]

Ti₃C₂

HF etching, TPAOH intercalation

Manganese oxide (MnO_x), soybean phospholipid (SP)

MRI-guided PTT

[55]

Ta₄C₃

HF etching

Supermagnetic iron oxide nanoparticles (IONPs)

MRI-guided PTT

[56]

Ti₃C₂

HF etching, TPAOH intercalation

Poly(lactic-co-glycolic acid) (PLGA), SP, IONPs

MRI-guided PTT

[34]

Nb₂C

HF etching, TPAOH intercalation

Polyvinylpyrrolidone (PVP)

PAI-guided PTT

[57]

Nb₂C

HF etching, TPAOH intercalation

Cetanecyltrimethylammonium chloride (CTAC), APTES, polyethylene glycol (PEG)

PAI-guided PTT

[58]

Ti₃C₂ QDs

Hydrothermal synthesis

–

Multicolour cellular imaging

[59]

Ti₃C₂ QDs

Sonication probing in TPAOH

–

PTT in NIR biowindow, biocompatibility test

[60]

Ti₂N QDs

KF + HCl etching, sonication in NMP

SP

PAI-guided PTT

[61]

Nb₂C QDs

HF etching, TPAOH sonication (ultrasound-assisted)

–

Fluorescence imaging, metal ions sensing

[62]

Ti₃C₂

HF etching, TPAOH intercalation

SP, doxorubicin (Dox)

Drug delivery

Chemotherapeutic agent, synergistic chemotherapy and PTT

[63]

Ti₃C₂

HF etching

Cellulose, Dox

Chemotherapeutic agent, synergistic chemotherapy and PTT

[64]

Ti₃C₂

HF etching

Polyacrylamide (PAM)

Study of drug release

[65]

Ti₃C₂

LiF + HCl etching

Cobalt nanowires (CoNWs), Dox

Study of drug release control, synergistic chemotherapy and PTT

[66]

Ti₃C₂

LiF + HCl etching

–

Antimicrobial activity

Study of antibacterial activity

[67]

Ti₃C₂

LiF + HCl etching

PVDF

For wastewater treatment

[68]

Ti₃C₂

LiF + HCl etching

Chitosan, glutaraldehyde

Study of antibacterial activity

[69]

Ti₃C_2, Ti₂C

HF etching

–

Comparison study of antibacterial activity

[70]

Ti₃C₂

HF etching

PLL

Study of antibacterial activity

[22]

Ti₃C₂

LiF + HCl etching

–

Study of antibacterial activity

[71]

Ti₃C₂

HF etching

–

Study of antifungal activity

[20]