Tetrodotoxin （TTX） is a small-molecule neurotoxin that is highly toxic. Accidental ingestion of TTX can cause neuroparalysis， with severe cases potentially life-threatening. Therefore， developing efficient， sensitive， and rapid screening techniques for TTX is crucial for safeguarding food safety. In recent years， with the intensive research on sensing mechanisms such as optical sensing and electrochemical sensing， numerous studies have integrated these sensing mechanisms with functional nanomaterials， signal amplification technologies， and specific recognition elements （aptamers， antibodies， peptides， etc.） to construct diverse detection systems that enable rapid， sensitive， and specific detection of TTX. This article focuses on the development process and application status in the detection of TTX by optical sensors， represented by surface-enhanced Raman scattering （SERS） sensors， surface plasmon resonance （SPR） sensors， and colorimetric and fluorescence sensors， as well as electrochemical sensors， represented by impedance sensors， amperometric sensors， electrochemiluminescence （ECL） sensors， and photoelectrochemical （PEC） sensors. Additionally， the development and performance characteristics of multi-modal sensors （such as fluorescence-SERS， electrochemical-SERS， and electrochemical-colorimetric dual-mode） are discussed， through cross-validation between signals， the accuracy and reliability of detection results have been improved. Especially the sensor performances （linear range， limit of detection （LOD）， stability） were optimized by using different functional materials （such as noble metal nanoparticles， graphene， metal organic frameworks （MOFs）， and biomaterials like aptamers and antibodies）. Finally， we point out the core challenges faced by current screening technologies of TTX. And the bright prospects of promoting the rapid screening technology of TTX from the laboratory to practical applications through the integration of multiple technologies were anticipated. In a word， these studies would make TTX poisoning incidents decrease and ensure public health.

Contents

1 Introduction

2 The developed analytical method based on optical sensing for the detection of TTX

2.1 SERS sensor

2.2 SPR sensor

2.3 Colorimetric sensor

2.4 Fluorescence sensor

3 The developed analytical method based on electrochemical sensing for the detection of TTX

3.1 Impedance sensor

3.2 Amperometric sensor

3.3 ECL sensor

3.4 PEC sensor

4 The developed analytical method based on multi-modal sensing for the detection of TTX

4.1 The fluorescence-SERS dual-modal sensor

4.2 The electrochemical-SERS dual-modal sensor

4.3 The electrochemical-colorimetric dual-modal sensor

4.4 The SERS-colorimetric dual-modal sensor

4.5 Multi-modal sensors based on other principles

4.6 The current status of multi-modal sensing for the detection of TTX

5 Challenges and outlook

6 Conclusion