## 1 Introduction  
Biofilms refer to a group of microorganisms adhered to a substrate within a polymeric matrix [1]. Biofilms possess unfavorable conditions like biofouling, pipe plugging, damage of equipment, prosthesis colonization, and a number of diseases [2]. Due to their greater resistance to antimicrobial treatment than planktonic cells of the same species, biofilms are usually challenging to eradicate [3; 4; 5]. Approximately 13 million people suffer from biofilm-related infections in the United States [6]. The Centers for Diseases Control and Prevention (CDC) estimates that approximately 65% of human bacterial diseases are due to biofilms, with a higher estimate (80%) proposed by the National Institutes of Health (NIH) [7]. More than 60% of hospital-acquired infections (HAI) are led by the attachment of a number of microorganisms to medical implants/devices like catheters, prostheses, fracture-fixation devices, dental implants, and cardiac devices [5; 8; 9; 10; 11; 12; 13; 14]. In Europe and USA, the World Health Organization estimates that about 4.5 million and 1.7 million patients are impacted by healthcare associated infections that lead to 100,000 and 37,000 deaths per annum [15]. Most of the infections that occur in nosocomial settings are due to the growth of bacteria such as _Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pyogenes_, and _Candida albicans_ in biofilm form [16].  
Critical requirements for developing an antimicrobial tool against biofilms in hospital settings are robustness and the disinfection and sterilization ability without any human side effects or damage to the medical devices and implants. Traditional sterilization methods such as heat and chemical treatments (quaternary ammonium compounds, aldehydes, alcohols and halogens or radiation, chlorhexiidine and silver salts, peroxygens, glutaraldehydehyde, and ortho-phthalaldehyde) [8; 17; 18] cannot be considered as perfect bacterial decontamination techniques because of their potential to eventually degrade the treated surface. Moreover, chemical usage can be toxic and lead to environmental pollution. As biofilms are significantly more resistant to antimicrobial treatment than in the planktonic form of the same species [3], removing them by conventional treatments would be problematic. Also, antibiotic treatment may not always inactivate overall bacterial cells present in the biofilm as they are more resistant to antibiotics. In addition to their limited efficacy, other drawbacks of current sterilization and disinfection methods include their environmental impact, clinical downtime and economic costs [19]. Therefore, a novel antimicrobial treatment technique, such as a non-thermal plasma (NTP), one which is safer, efficient, and cost-effective in clinical settings, will be of great interest.  
The main scope of this paper is to provide a review of the published research in the area of biofilm decontamination and sterilization using plasma. The emphasis here is on the potential of NTP for biofilm inactivation. The basics of this novel technology is reviewed, and a brief overview is given of extensive published research in the field. Other sections provide explanations and reviews of biofilms and their formation, the varieties of NTP, plasma generation, various plasma reactive species, factors influencing the antimicrobial efficacy of plasma, and summaries of several significant publications in the field.